creating cache folder when checking access

Author: NeilSmithDLS

src/blueapi/service/authentication.py

@@ -71,6 +71,8 @@ def _default_token_cache_path() -> Path:
     def can_access_cache(self) -> bool:
         assert self._token_path
         try:
+            Path(self._token_path.parent).mkdir(parents=True, exist_ok=True)
+            os.chmod(self._token_path.parent, 0o600)
             self._token_path.write_text("")
         except IsADirectoryError:
             print("Invalid path: a directory path was provided instead of a file path")