Remove @cpp.RuntimeAnnotation

Summary: All usages of cpp.RuntimeAnnotation has been migrated to thrift.RuntimeAnnotation

Reviewed By: ahilger

Differential Revision: D78749239

fbshipit-source-id: 0fd382be1377bd2c5895e9e929a56858444cf6e8

Author: thedavekwon

thrift/annotation/cpp.thrift

@@ -337,12 +337,6 @@ struct Frozen2RequiresCompleteContainerParams {}
 @scope.Interaction
 struct ProcessInEbThreadUnsafe {}
 
-/**
- * Applies to structured annotation that need to be accessed in always-on reflection.
- */
-@scope.Struct
-struct RuntimeAnnotation {}
-
 /**
  * Causes uses of the given structured type to be replaced with `CursorSerializationWrapper` to allow use of cursor-based serialization.
  * Must add `cpp_include "thrift/lib/cpp2/protocol/CursorBasedSerializer.h"` to files that use this annotation.