Don't skip pickle check_frame_opcodes() (GH-15027)

This looks like the only place that proto 4 framing gets exercised
so leave it as part of the PGO task.
(cherry picked from commit eca7ffc61cf925eae5def8c64b05d47f24e60e1f)

Co-authored-by: Neil Schemenauer <nas-github@arctrix.com>
diff --git a/Lib/test/pickletester.py b/Lib/test/pickletester.py
index 5d402a4..c9f3746 100644
--- a/Lib/test/pickletester.py
+++ b/Lib/test/pickletester.py
@@ -2281,7 +2281,6 @@
     FRAME_SIZE_MIN = 4
     FRAME_SIZE_TARGET = 64 * 1024
 
-    @support.skip_if_pgo_task
     def check_frame_opcodes(self, pickled):
         """
         Check the arguments of FRAME opcodes in a protocol 4+ pickle.