chore: use auth file bind mapping

Co-authored-by: Alejandro Santisteban <alex.santisteban@canonical.com>

Author: zhijie-yang

src/docs/generate_oci_doc_yaml.py

@@ -205,7 +205,7 @@ def run_skopeo_command(self, cmd: str, args: List[str]) -> Dict:
                 "run",
                 "--rm",
                 "-v",
-                f"{tmp_dir}:/skopeo-auth:ro",
+                f"{auth_file}:/skopeo-auth/auth.json:ro",
                 os.environ.get("SKOPEO_IMAGE", DEFAULT_SKOPEO_IMAGE),
                 cmd,
                 "--authfile",