tests/sync(fix[test_hg]): Use private remote in pull-failure test

why: test_update_repo_pull_failure_returns_sync_result deleted the
session-scoped hg_remote_repo, breaking all subsequent tests that
depend on it (e.g. tests/url/test_hg.py::test_hg_url).
what:
- Use create_hg_remote_repo factory to create a disposable remote
- Matches the pattern used by the equivalent git test

Author: tony

tests/sync/test_hg.py

@@ -4,15 +4,20 @@
 
 import pathlib
 import shutil
+import typing as t
 
 import pytest
 
 from libvcs import exc
 from libvcs._internal.run import run
 from libvcs._internal.shortcuts import create_project
+from libvcs.pytest_plugin import hg_remote_repo_single_commit_post_init
 from libvcs.sync.base import SyncResult
 from libvcs.sync.hg import HgSync
 
+if t.TYPE_CHECKING:
+    from libvcs.pytest_plugin import CreateRepoPytestFixtureFn
+
 if not shutil.which("hg"):
     pytestmark = pytest.mark.skip(reason="hg is not available")
 
@@ -107,23 +112,23 @@ def test_vulnerability_2022_03_12_command_injection(
 
 
 def test_update_repo_pull_failure_returns_sync_result(
-    tmp_path: pathlib.Path,
     projects_path: pathlib.Path,
-    hg_remote_repo: pathlib.Path,
+    create_hg_remote_repo: CreateRepoPytestFixtureFn,
 ) -> None:
     """Test that a deleted remote in update_repo() returns SyncResult with error."""
     repo_name = "my_hg_error_project"
+    hg_remote = create_hg_remote_repo(
+        remote_repo_post_init=hg_remote_repo_single_commit_post_init,
+    )
 
     hg_repo = HgSync(
-        url=f"file://{hg_remote_repo}",
+        url=f"file://{hg_remote}",
         path=projects_path / repo_name,
     )
 
-    # First update_repo clones since .hg doesn't exist yet
     hg_repo.update_repo()
 
-    # Delete the remote to cause a pull failure
-    shutil.rmtree(hg_remote_repo)
+    shutil.rmtree(hg_remote)
 
     result = hg_repo.update_repo()