Use Members::DestroyService when destroying members on LDAP group sync

Problem

When users are removed from groups during LDAP synchronization, their user_group_member_roles records are not properly cleaned up. This happens because the current implementation directly destroys member records instead of using the Members::DestroyService, which handles all necessary cleanup operations.

What does this MR do and why?

This MR updates the LDAP group synchronization service to use Members::DestroyService when removing a user's access from a group. This ensures:

1. All associated user_group_member_roles records are properly cleaned up (reference)
2. The removal process during LDAP sync follows the same pattern as other member removal flows in the system
3. Any future cleanup logic added to Members::DestroyService will automatically apply to LDAP sync removals

References

Update user_group_member_roles when member is d... (#557859 - closed).

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