Test: fix stale uops usage in test_capi:

Recompute uops for `test_is_none` instead of reusing the previous test's value.

Signed-off-by: Yongtao Huang <yongtaoh2022@gmail.com>

Author: hyongtao-code

Lib/test/test_capi/test_opt.py

@@ -3750,6 +3750,7 @@ def test_is_none(n):
         res, ex = self._run_with_optimizer(test_is_none, TIER2_THRESHOLD)
         self.assertEqual(res, True)
         self.assertIsNotNone(ex)
+        uops = get_opnames(ex)
 
         self.assertIn("_IS_OP", uops)
         self.assertIn("_POP_TOP_NOP", uops)