Do not run test_gdb when gdb embeds Python 2. (GH-31956)

Author: methane

Lib/test/test_gdb.py

@@ -117,6 +117,9 @@ def run_gdb(*args, **env_vars):
 if not gdbpy_version:
     raise unittest.SkipTest("gdb not built with embedded python support")
 
+if "major=2" in gdbpy_version:
+    raise unittest.SkipTest("gdb built with Python 2")
+
 # Verify that "gdb" can load our custom hooks, as OS security settings may
 # disallow this without a customized .gdbinit.
 _, gdbpy_errors = run_gdb('--args', sys.executable)