Replace Py_NotImplemented returns with the macro form Py_RETURN_NOTIMPLEMENTED.
The macro was introduced in #12724.
diff --git a/Objects/floatobject.c b/Objects/floatobject.c
index 3392614..a031d1b 100644
--- a/Objects/floatobject.c
+++ b/Objects/floatobject.c
@@ -517,8 +517,7 @@
     return PyBool_FromLong(r);
 
  Unimplemented:
-    Py_INCREF(Py_NotImplemented);
-    return Py_NotImplemented;
+    Py_RETURN_NOTIMPLEMENTED;
 }
 
 static Py_hash_t