[3.13] gh-117953: Skip test_interpreters properly without GIL (gh-120707)

(cherry picked from commit 1035fe0, AKA gh-120689)

Co-authored-by: Nice Zombies <[email protected]>

Author: miss-islington

Lib/test/test_interpreters/__init__.py

@@ -1,6 +1,9 @@
 import os
 from test.support import load_package_tests, Py_GIL_DISABLED
+import unittest
 
-if not Py_GIL_DISABLED:
-    def load_tests(*args):
-        return load_package_tests(os.path.dirname(__file__), *args)
+if Py_GIL_DISABLED:
+    raise unittest.SkipTest("GIL disabled")
+
+def load_tests(*args):
+    return load_package_tests(os.path.dirname(__file__), *args)