Remove unused method

Author: fangerer

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/cext/hpy/GraalHPyContext.java

@@ -3191,10 +3191,6 @@ boolean releaseHPyHandleForObject(int handle) {
         return true;
     }
 
-    void onInvalidHandle(@SuppressWarnings("unused") int id) {
-        // nothing to do in the universal context
-    }
-
     private static final class HandleStack {
         private int[] handles;
         private int top = 0;