refactor: remove customAuthParams from OIDC provider configuration

- Eliminated the customAuthParams field from the OIDC provider configuration in the OidcConfigPersistence class to streamline the provider setup.
- Updated related logic to ensure compatibility with the revised configuration structure.

Author: elibosley

api/src/unraid-api/graph/resolvers/sso/oidc-config.service.ts

@@ -171,7 +171,6 @@ export class OidcConfigPersistence extends ConfigFilePersister<OidcConfig> {
             buttonIcon: provider.buttonIcon,
             buttonVariant: provider.buttonVariant,
             buttonStyle: provider.buttonStyle,
-            customAuthParams: provider.customAuthParams,
         };
 
         const existingIndex = providers.findIndex((p) => p.id === provider.id);