Update expected test count after removing JsonTypedUntypedTests

The upstream API removed fromUntyped/toUntyped methods, so we deleted
the test file that tested those methods (12 tests removed: 509 -> 497).

Author: simbo1905

.github/workflows/ci.yml

@@ -39,7 +39,7 @@ jobs:
                       for k in totals: totals[k]+=int(r.get(k,'0'))
                   except Exception:
                       pass
-          exp_tests=509
+          exp_tests=497
           exp_skipped=0
           if totals['tests']!=exp_tests or totals['skipped']!=exp_skipped:
               print(f"Unexpected test totals: {totals} != expected tests={exp_tests}, skipped={exp_skipped}")