fix(ci): suppress ruff S108 for test paths and use tempfile.gettempdir()

Pre-commit.ci flagged /tmp literals in test assertions as S108
(insecure temp path). These are test-only strings used to verify
path traversal rejection, not actual temp file usage.

Signed-off-by: Yash Goel <yashhzd@users.noreply.github.com>

Author: yashhzd

tests/test_backend_filesystem.py

@@ -1053,7 +1053,7 @@ def test_download_rejects_absolute_path(self, tmp_path) -> None:
             str(tmp_path), "vehicle_type", None, allow_editing_template_files=False, save_component_to_system_templates=False
         )
         lfs.configuration_steps = {
-            "test.param": {"download_file": {"source_url": "https://example.com/payload", "dest_local": "/tmp/evil"}}
+            "test.param": {"download_file": {"source_url": "https://example.com/payload", "dest_local": "/tmp/evil"}}  # noqa: S108
         }
 
         with pytest.raises(ValueError, match="Path escapes vehicle directory"):
@@ -1085,10 +1085,10 @@ def test_download_rejects_symlink_escape(self, tmp_path) -> None:
         WHEN: dest_local references a file through the symlink
         THEN: A ValueError is raised because the resolved path escapes vehicle_dir
         """
-        # Create a symlink inside tmp_path pointing to /tmp
+        # Create a symlink inside tmp_path pointing outside vehicle_dir
         symlink_path = tmp_path / "escape_link"
         try:
-            symlink_path.symlink_to("/tmp")
+            symlink_path.symlink_to(tempfile.gettempdir())
         except OSError:
             pytest.skip("Cannot create symlinks in this environment")