docs: remove auth from keycloack url (#4391)

in keycloak 17.0+ , There's a change in endpoints as per the official documentation (https://www.keycloak.org/docs-api/11.0/rest-api/index.html#_users_resource) .
so the new url well be https://my-keycloak-domain.com/realms/My_Realm

docs/docs/providers/keycloak.md

@@ -37,5 +37,5 @@ providers: [
 ```
 
 :::note
-`issuer` should include the realm – e.g. `https://my-keycloak-domain.com/auth/realms/My_Realm`
+`issuer` should include the realm – e.g. `https://my-keycloak-domain.com/realms/My_Realm`
 :::