update types mentioned in comment to match method (#82768)

seems that the comment got copied over from FrozenSet and not updated

Author: chillitom

src/libraries/System.Collections.Immutable/src/System/Collections/Frozen/FrozenDictionary.cs

@@ -98,7 +98,7 @@ public static FrozenDictionary<TKey, TValue> ToFrozenDictionary<TKey, TValue>(th
                 ChooseImplementationOptimizedForConstruction(uniqueValues!, sourceIsCopy));
         }
 
-        /// <summary>Extracts from the source either an existing <see cref="FrozenSet{T}"/> instance or a <see cref="HashSet{T}"/> containing the values and the specified <paramref name="comparer"/>.</summary>
+        /// <summary>Extracts from the source either an existing <see cref="FrozenDictionary{TKey,TValue}"/> instance or a <see cref="Dictionary{TKey,TValue}"/> containing the values and the specified <paramref name="comparer"/>.</summary>
         /// <returns>true if <paramref name="uniqueValues"/> is a copy of the original source; false if it's either null or the original source.</returns>
         private static bool GetUniqueValues<TKey, TValue>(
             IEnumerable<KeyValuePair<TKey, TValue>> source, IEqualityComparer<TKey>? comparer,