Improvements to OAuth2 hooks

• Fixed an issue where updating the Identities configuration removed the token_hook setting in the OAuth2 configuration. The configuration now retains the token_hook when Identities settings are updated.

• Fixed an issue where importing the OAuth2 configuration added a new token_hook instead of overriding the existing one. The import process now correctly replaces existing token_hook definitions.

This fix is now live in Ory Network.