Remove @WeakOuter from ImmutableMultiset.ElementSet. @WeakOuter is us…

…eful for inner classes but not for static nested classes.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=202500806

guava/src/com/google/common/collect/ImmutableMultiset.java

@@ -584,9 +584,9 @@ ImmutableMultiset<E> buildJdkBacked() {
     }
   }
 
-  @WeakOuter
   static final class ElementSet<E> extends ImmutableSet.Indexed<E> {
     private final List<Entry<E>> entries;
+    // TODO(cpovirk): @Weak?
     private final Multiset<E> delegate;
 
     ElementSet(List<Entry<E>> entries, Multiset<E> delegate) {