souces/oauth: reddit: fix duplicate keyword auth (#13466)

* wip

Closes https://github.com/goauthentik/authentik/issues/13464

The issue was that the auth parameter was being passed twice:
Once directly in the get_access_token call: super().get_access_token(auth=auth)
And again in the parent class's get_access_token method where it sets auth=(self.get_client_id(), self.get_client_secret())

The fix:
Instead of passing auth directly to get_access_token, we now add it to the request_kwargs dictionary
Then we pass all the request kwargs to the parent method using **request_kwargs

* wip

lint

authentik/sources/oauth/types/reddit.py

@@ -25,8 +25,10 @@ class RedditOAuth2Client(UserprofileHeaderAuthClient):
 
     def get_access_token(self, **request_kwargs):
         "Fetch access token from callback request."
-        auth = HTTPBasicAuth(self.source.consumer_key, self.source.consumer_secret)
-        return super().get_access_token(auth=auth)
+        request_kwargs["auth"] = HTTPBasicAuth(
+            self.source.consumer_key, self.source.consumer_secret
+        )
+        return super().get_access_token(**request_kwargs)
 
 
 class RedditOAuth2Callback(OAuthCallback):