[3.11] gh-115538: Use pathlib to compare prefixes in test_venv (GH-117076)

gh-115538: Use pathlib to compare prefixes in test_venv (GH-117076)
(cherry picked from commit 52f5b7f)

Co-authored-by: AN Long <aisk@users.noreply.github.com>

Author: miss-islington

Lib/test/test_venv.py

@@ -253,7 +253,8 @@ def test_prefixes(self):
             ('base_exec_prefix', sys.base_exec_prefix)):
             cmd[2] = 'import sys; print(sys.%s)' % prefix
             out, err = check_output(cmd)
-            self.assertEqual(out.strip(), expected.encode(), prefix)
+            self.assertEqual(pathlib.Path(out.strip().decode()),
+                             pathlib.Path(expected), prefix)
 
     @requireVenvCreate
     def test_sysconfig(self):