test: exclude fixture paths from credential redaction assertions

The Ubuntu 3.14t CI job rejected correctly redacted clone output because
its randomly generated `/tmp/.tmpg8ibob` fixture path contained `bob`.
The credential assertions scanned the whole error and trace, so ordinary
source and destination paths could masquerade as leaked credentials.

Replace only the known fixture directory with `<fixture>` before checking
the error and trace for credentials. Keep the exact redacted-option
assertions and the credential checks outside that directory. Include
`alice-bob-user-token` in the input paths so this false positive is now
covered deterministically, rather than depending on a random name.

All four trace subtests failed before the assertion fix. The focused CLI
and Gix runs each pass three redaction tests and four subtests afterward.
`ruff check`, `ruff format --check`, and `git diff --check` also pass.
This commit changes only `test/test_git.py` and is intentionally not pushed.

Author: codex

test/test_git.py

@@ -518,7 +518,7 @@ def test_it_redacts_authorization_extra_header_from_error(self):
     def test_clone_redacts_config_urls_from_trace_and_error(self, option, expected):
         for trace in (True, "full"):
             with self.subTest(trace=trace), writable_fixture("repo.sh", "empty") as temporary:
-                directory = temporary.path()
+                directory = temporary.path() / "alice-bob-user-token"
                 with mock.patch.object(Git, "GIT_PYTHON_TRACE", trace):
                     with self.assertLogs("git.cmd", level="INFO") as logs:
                         with self.assertRaises(GitCommandError) as context:
@@ -529,9 +529,9 @@ def test_clone_redacts_config_urls_from_trace_and_error(self, option, expected):
                                 allow_unsafe_options=True,
                             )
                 self.assertIn(expected, context.exception.command)
-                message = str(context.exception)
+                message = str(context.exception).replace(str(directory), "<fixture>")
                 assert logs is not None
-                log_output = " ".join(logs.output)
+                log_output = " ".join(logs.output).replace(str(directory), "<fixture>")
                 self.assertIn(expected, log_output)
                 for credential in ("alice", "bob", "user", "token"):
                     self.assertNotIn(credential, message)