fix(client): send all configured auth headers (#643)

Author: stainless-app[bot]

src/finch/_client.py

@@ -147,11 +147,7 @@ def qs(self) -> Querystring:
     @property
     @override
     def auth_headers(self) -> dict[str, str]:
-        if self._bearer_auth:
-            return self._bearer_auth
-        if self._basic_auth:
-            return self._basic_auth
-        return {}
+        return {**self._bearer_auth, **self._basic_auth}
 
     @property
     def _bearer_auth(self) -> dict[str, str]:
@@ -455,11 +451,7 @@ def qs(self) -> Querystring:
     @property
     @override
     def auth_headers(self) -> dict[str, str]:
-        if self._bearer_auth:
-            return self._bearer_auth
-        if self._basic_auth:
-            return self._basic_auth
-        return {}
+        return {**self._bearer_auth, **self._basic_auth}
 
     @property
     def _bearer_auth(self) -> dict[str, str]: