Follow-up f6bd18d: Add in-code comment on aliases for when they were added

Change-Id: I16cd2aba7b353b52359604d0290f9996e6bc0044

includes/CommentStore/CommentStore.php

@@ -41,4 +41,7 @@ namespace MediaWiki\CommentStore;
 class CommentStore extends CommentStoreBase {
 }
 
+/**
+ * @deprecated since 1.40
+ */
 class_alias( CommentStore::class, 'CommentStore' );

includes/CommentStore/CommentStoreComment.php

@@ -96,4 +96,7 @@ class CommentStoreComment {
 	}
 }
 
+/**
+ * @deprecated since 1.40
+ */
 class_alias( CommentStoreComment::class, 'CommentStoreComment' );