bpo-43651: PEP 597: Fix EncodingWarning in some tests (GH-25189)

* Fix _sitebuiltins
* Fix test_inspect
* Fix test_interpreters
* Fix test_io
* Fix test_iter
* Fix test_json
* Fix test_linecache
* Fix test_lltrace
* Fix test_logging
* Fix logging
diff --git a/Lib/test/test_lltrace.py b/Lib/test/test_lltrace.py
index 5f7d564..8f1a92e 100644
--- a/Lib/test/test_lltrace.py
+++ b/Lib/test/test_lltrace.py
@@ -13,7 +13,7 @@ def test_lltrace_does_not_crash_on_subscript_operator(self):
         # bpo-34113. The crash happened at the command line console of
         # debug Python builds with __ltrace__ enabled (only possible in console),
         # when the interal Python stack was negatively adjusted
-        with open(os_helper.TESTFN, 'w') as fd:
+        with open(os_helper.TESTFN, 'w', encoding='utf-8') as fd:
             self.addCleanup(os_helper.unlink, os_helper.TESTFN)
             fd.write(textwrap.dedent("""\
             import code