gh-90473: WASI: skip gethostname tests (GH-93092)

- WASI's ``gethostname()`` is a stub that always fails with OSError
  ``ENOTSUP``
- skip mailcap ``test`` if subprocess is not available
- WASI process_time clock does not work.
(cherry picked from commit 760ec8940a)

Co-authored-by: Christian Heimes <christian@python.org>

Lib/test/test_urllib_response.py

@@ -4,6 +4,11 @@ import socket
 import tempfile
 import urllib.response
 import unittest
+from test import support
+
+if support.is_wasi:
+    raise unittest.SkipTest("Cannot create socket on WASI")
+
 
 class TestResponse(unittest.TestCase):