gh-53502: Fixes for tests in gh-113363

1. Use 32-bit compatible date in test_dump_naive_datetime_with_aware_datetime_option

2. test_dump_naive_datetime_with_aware_datetime_option: Writing non-aware datetimes
   with aware_datetime==True leads to the time being off by twice
   the timezone offset from UTC

Author: ronaldoussoren

Lib/test/test_plistlib.py

@@ -881,11 +881,11 @@ def test_dump_naive_datetime_with_aware_datetime_option(self):
         # Save a naive datetime with aware_datetime set to true.  This will lead
         # to having different time as compared to the current machine's
         # timezone, which is UTC.
-        dt = datetime.datetime(2345, 6, 7, 8, tzinfo=None)
+        dt = datetime.datetime(2003, 6, 7, 8, tzinfo=None)
         for fmt in ALL_FORMATS:
             s = plistlib.dumps(dt, fmt=fmt, aware_datetime=True)
             parsed = plistlib.loads(s, aware_datetime=False)
-            expected = dt + datetime.timedelta(seconds=time.timezone)
+            expected = dt + 2 * datetime.timedelta(seconds=time.timezone)
             self.assertEqual(parsed, expected)