LibOverride: Do not tag overrides for complete recalc.

This was done as some sort of safety, but should not actually be needed,
and including tags like `ID_RECALC_POINT_CACHE` e.g. makes usage of
point caches impossible with liboverrides (since it would systematically
invalidate all cache on file load).

In theory we should not have to tag anything here in fact, RNA accessors
are supposed to take care of it, but for now we keep the
`ID_RECALC_COPY_ON_WRITE` one.

Part of first step of T82503: support disk cache in liboverrides.

source/blender/blenkernel/intern/lib_override.c

@@ -1801,7 +1801,7 @@ void BKE_lib_override_library_update(Main *bmain, ID *local)
   /* Full rebuild of Depsgraph! */
   /* Note: this is really brute force, in theory updates from RNA should have handled this already,
    * but for now let's play it safe. */
-  DEG_id_tag_update_ex(bmain, local, ID_RECALC_ALL);
+  DEG_id_tag_update_ex(bmain, local, ID_RECALC_COPY_ON_WRITE);
   DEG_relations_tag_update(bmain);
 }