gh-125900: Clean-up logic around immortalization in free-threading (#125901)

* Remove `@suppress_immortalization` decorator
* Make suppression flag per-thread instead of per-interpreter
* Suppress immortalization in `eval()` to avoid refleaks in three tests
  (test_datetime.test_roundtrip, test_logging.test_config8_ok, and
   test_random.test_after_fork).
* frozenset() is constant, but not a singleton. When run multiple times,
  the test could fail due to constant interning.

1 files changed, 1 insertions, 2 deletions

diff --git a/Lib/test/test_zoneinfo/test_zoneinfo.py b/Lib/test/test_zoneinfo/test_zoneinfo.py
index 8bcd6d2e995..84147215557 100644
--- a/Lib/test/test_zoneinfo/test_zoneinfo.py
+++ b/Lib/test/test_zoneinfo/test_zoneinfo.py
@@ -17,7 +17,7 @@ import unittest
 from datetime import date, datetime, time, timedelta, timezone
 from functools import cached_property
 
-from test.support import MISSING_C_DOCSTRINGS, requires_gil_enabled
+from test.support import MISSING_C_DOCSTRINGS
 from test.test_zoneinfo import _support as test_support
 from test.test_zoneinfo._support import OS_ENV_LOCK, TZPATH_TEST_LOCK, ZoneInfoTestBase
 from test.support.import_helper import import_module, CleanImport
@@ -1931,7 +1931,6 @@ class ExtensionBuiltTest(unittest.TestCase):
         self.assertFalse(hasattr(c_zoneinfo.ZoneInfo, "_weak_cache"))
         self.assertTrue(hasattr(py_zoneinfo.ZoneInfo, "_weak_cache"))
 
-    @requires_gil_enabled("gh-117783: types may be immortalized")
     def test_gc_tracked(self):
         import gc