gh-155423: Make BaseFileTest.tearDown() in test_logging robust (GH-155424)

Always call BaseTest.tearDown(), which removes the handlers added by
setUp(), even if unlinking the log files fails.  Tolerate an already
removed file.
(cherry picked from commit 6f7fb6c)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>

Author: serhiy-storchaka

Lib/test/test_logging.py

@@ -6358,11 +6358,12 @@ def setUp(self):
         self.rmfiles = []
 
     def tearDown(self):
-        for fn in self.rmfiles:
-            os.unlink(fn)
-        if os.path.exists(self.fn):
-            os.unlink(self.fn)
-        BaseTest.tearDown(self)
+        try:
+            for fn in self.rmfiles:
+                os_helper.unlink(fn)
+            os_helper.unlink(self.fn)
+        finally:
+            BaseTest.tearDown(self)
 
     def assertLogFile(self, filename):
         "Assert a log file is there and register it for deletion"