Remove unused canUseUnsafe() protected method from GeneratedMessage

This was briefly used by generated code internally as part of the experimental parser/runtime work. This method was never used by protoc generated code otherwise.

We don't consider removal of protected methods for the gencode base classes to be a breaking change if they were never called by any released generated code, as it would only break someone who subclassed GeneratedMessage by hand and wrote code who called this which is not supported. In this case there's essentially no reason for someone to have been interested in calling this anyway.

PiperOrigin-RevId: 843318803

Author: protobuf-github-bot

java/core/src/main/java/com/google/protobuf/GeneratedMessage.java

@@ -371,10 +371,6 @@ protected static <M extends Message> M parseDelimitedWithIOException(
     }
   }
 
-  protected static boolean canUseUnsafe() {
-    return UnsafeUtil.hasUnsafeArrayOperations() && UnsafeUtil.hasUnsafeByteBufferOperations();
-  }
-
   protected static IntList emptyIntList() {
     return IntArrayList.emptyList();
   }