Lowering memory usage of malli cache

```
registry=> (update-vals @cache mm/measure)
{:validator "16.4 MiB",
 :metabase.api.macros/decoder "98.6 KiB",
 :metabase.lib.normalize/coercer "144.3 MiB",
 :explainer "10.2 MiB"}
```

Explanation of each:

binding `[filter? (mr/validator ::mbql.s/Filter)]`
This doesn't actually lower ram usage, just dramatically drops the cache
usage. This filter is hit ~170,000 times when loading the examples
dashboard. It walks over each query and for each piece in the query it
hits the cache. Very wasteful but not exactly slow.

```diff
-   #'metadata-provider?])
+   metadata-provider?])
```
I found that changing this from a var to the var's value here can drop
the validator usage from ~125mb to ~10mb. The weird thing is that it
would happen on the second time, not the first. Leaving it here as it
seems innocuous.

```
@@ -53,12 +52,9 @@
   default-error-fn)

 (defn- coercer [schema]
-  (mr/cached ::coercer
-             schema
-             (fn []
-               (let [respond identity
-                     raise   #'*error-fn*] ; capture var rather than the bound value at the time this is eval'ed
-                 (mc/coercer schema (mtx/transformer mtx/default-value-transformer {:name :normalize}) respond raise)))))
+  (let [respond identity
+        raise   #'*error-fn*] ; capture var rather than the bound value at the time this is eval'ed
+    (mc/coercer schema (mtx/transformer mtx/default-value-transformer {:name :normalize}) respond raise)))
```

This is a tradeoff. It is slower without this.

```
normalize=> (time
              (do
                (dotimes [_ 50]
                  (normalize
                    :metabase.lib.schema/stage stage))
                :done))
"Elapsed time: 526.081834 msecs"
:done
;; redefine coercer to use cache
normalize=> (time
              (do
                (dotimes [_ 50]
                  (normalize
                    :metabase.lib.schema/stage stage))
                :done))
"Elapsed time: 37.066083 msecs"
:done
```

I'm hopeful that while it is slower, it's not meaningfully slower. Doing
this 50 times is half a second. Hopefully this is academic.

```diff
@@ -400,7 +400,7 @@
     ;; TODO (Cam 6/12/25) -- why in the HECC is `:lib/metadata` not a required key here? It's virtually REQUIRED for
     ;; anything to work correctly outside of the low-level conversion code. We should make it required and then fix
     ;; whatever breaks.
-    [:lib/metadata {:optional true} ::lib.schema.metadata/metadata-provider]
+    #_[:lib/metadata {:optional true} ::lib.schema.metadata/metadata-provider]
```

This one i found just completely transformed memory usage.
The validator and explainers dropped from ~130mb to ~15 or 10mb.
```clojure
registry=> (update-vals @cache mm/measure)
{:validator "16.4 MiB",
 :metabase.api.macros/decoder "98.6 KiB",
 :metabase.lib.normalize/coercer "144.3 MiB",
 :explainer "10.2 MiB"}
```

```diff
@@ -429,7 +429,7 @@
     [:update-row {:optional true} [:maybe [:ref ::actions/row]]]]
    ;;
    ;; CONSTRAINTS
-   [:ref ::lib.schema.util/unique-uuids]
+   #_[:ref ::lib.schema.util/unique-uuids]
```
This one could undo the changes above. I don't know why

src/metabase/legacy_mbql/normalize.cljc

@@ -42,6 +42,7 @@
    [metabase.util.i18n :as i18n]
    [metabase.util.log :as log]
    [metabase.util.malli :as mu]
+   [metabase.util.malli.registry :as mr]
    [metabase.util.performance :as perf]
    [metabase.util.time :as u.time]))
 
@@ -1054,11 +1055,12 @@
   "Replaces legacy filter clauses with modern alternatives."
   [query]
   (try
-    (lib.util.match/replace query
-      (filter-clause :guard mbql.preds/Filter?)
-      (-> filter-clause
-          replace-relative-date-filters
-          replace-exclude-date-filters))
+    (let [filter? (mr/validator ::mbql.s/Filter)]
+     (lib.util.match/replace query
+       (filter-clause :guard filter? #_ mbql.preds/Filter?)
+       (-> filter-clause
+           replace-relative-date-filters
+           replace-exclude-date-filters)))
     (catch #?(:clj Throwable :cljs :default) e
       (throw (ex-info (i18n/tru "Error replacing legacy filters")
                       {:query query}

src/metabase/lib/metadata/protocols.cljc

@@ -77,7 +77,7 @@
   "Schema for something that satisfies the [[metabase.lib.metadata.protocols/MetadataProvider]] protocol."
   [:fn
    {:error/message "Valid MetadataProvider"}
-   #'metadata-provider?])
+   metadata-provider?])
 
 (defn metadata-providerable?
   "Whether `x` is a [[metadata-provider?]], or has one attached at `:lib/metadata` (i.e., a query)."

src/metabase/lib/normalize.cljc

@@ -8,8 +8,7 @@
    [metabase.lib.schema.metadata :as lib.schema.metadata]
    [metabase.util :as u]
    [metabase.util.i18n :as i18n]
-   [metabase.util.log :as log]
-   [metabase.util.malli.registry :as mr]))
+   [metabase.util.log :as log]))
 
 (defn- lib-type [x]
   (when (map? x)
@@ -53,12 +52,9 @@
   default-error-fn)
 
 (defn- coercer [schema]
-  (mr/cached ::coercer
-             schema
-             (fn []
-               (let [respond identity
-                     raise   #'*error-fn*] ; capture var rather than the bound value at the time this is eval'ed
-                 (mc/coercer schema (mtx/transformer mtx/default-value-transformer {:name :normalize}) respond raise)))))
+  (let [respond identity
+        raise   #'*error-fn*] ; capture var rather than the bound value at the time this is eval'ed
+    (mc/coercer schema (mtx/transformer mtx/default-value-transformer {:name :normalize}) respond raise)))
 
 (defn normalize
   "Ensure some part of an MBQL query `x`, e.g. a clause or map, is in the right shape after coming in from JavaScript or

src/metabase/lib/schema.cljc

@@ -400,7 +400,7 @@
     ;; TODO (Cam 6/12/25) -- why in the HECC is `:lib/metadata` not a required key here? It's virtually REQUIRED for
     ;; anything to work correctly outside of the low-level conversion code. We should make it required and then fix
     ;; whatever breaks.
-    [:lib/metadata {:optional true} ::lib.schema.metadata/metadata-provider]
+    #_[:lib/metadata {:optional true} ::lib.schema.metadata/metadata-provider]
     [:database {:optional true} [:multi {:dispatch (partial = id/saved-questions-virtual-database-id)}
                                  [true  ::id/saved-questions-virtual-database]
                                  [false ::id/database]]]
@@ -429,7 +429,7 @@
     [:update-row {:optional true} [:maybe [:ref ::actions/row]]]]
    ;;
    ;; CONSTRAINTS
-   [:ref ::lib.schema.util/unique-uuids]
+   #_[:ref ::lib.schema.util/unique-uuids]
    (common/disallowed-keys
     {:filter       ":filter is not allowed in MBQL 5, and it's not allowed in the top-level of a stage in any MBQL version"
      :source-query ":source-query is not allowed in MBQL 5, and it's not allowed in the top-level of a stage in any MBQL version"