Change get_auth signature: replace '*_' with '*' to avoid untyped varargs

[stoyan-atanasov-beye]

Title: Change get_auth signature: replace *_ with * to avoid untyped varargs

Summary:

Please change the get_auth function signature to use a bare * instead of *_, so that the function requires keyword-only args without introducing an untyped varargs parameter.

Why:

• Currently get_auth is defined as def get_auth(*_, client_id: str, ...) which accepts arbitrary positional args via *_.
• The untyped varargs show up to type-checkers (Pylance/Pyright) as Unknown and leads to diagnostics like reportUnknownVariableType in consumer projects (even when python.analysis.useLibraryCodeForTypes is enabled).
• Replacing *_, with * keeps the function semantics (forces subsequent parameters to be keyword-only) without introducing an untyped parameter that causes analyzer warnings.

Suggested one-line change in fastapi_oidc/auth.py:

- def get_auth(*_, client_id: str, audience: Optional[str] = None, base_authorization_server_uri: str, issuer: str, signature_cache_ttl: int, token_type: Type[IDToken] = IDToken) -> Callable[[str], IDToken]:
+ def get_auth(*, client_id: str, audience: Optional[str] = None, base_authorization_server_uri: str, issuer: str, signature_cache_ttl: int, token_type: Type[IDToken] = IDToken) -> Callable[[str], IDToken]:

Notes:

• This change is non-breaking: it still forces the same keyword-only parameters, but removes the untyped *_ varargs tuple that static analyzers flag as Unknown.
• If maintainers prefer an explicit typed varargs, *_: Any is an alternative that keeps a positional capture but types it explicitly for analyzers.

Can I open a PR with this small change (and optional *_: Any variant) if youd

[stoyan-atanasov-beye]

created a pr #53