bpo-42749: Use dynamic version to test for unsupported bignum in Tk (GH-23966)

Tk can internally support bignum even if Tkinter is built without
support of bignum.

diff --git a/Lib/test/test_tcl.py b/Lib/test/test_tcl.py
index 5bc4f9bda171ea99b756b568490979c606b52b21..ee7344c48ed0beb73d00584876bd58c6f18a9b05 100644 (file)
--- a/Lib/test/test_tcl.py
+++ b/Lib/test/test_tcl.py
@@ -449,7 +449,7 @@ class TclTest(unittest.TestCase):
             else:
                 self.assertEqual(result, str(i))
                 self.assertIsInstance(result, str)
-        if tcl_version < (8, 5):  # bignum was added in Tcl 8.5
+        if get_tk_patchlevel() < (8, 5):  # bignum was added in Tcl 8.5
             self.assertRaises(TclError, tcl.call, 'expr', str(2**1000))
 
     def test_passing_values(self):