Add support for inactive_resource_access_tokens_delete_after_days

Add support for missing field inactive_resource_access_tokens_delete_after_days from the application settings API: https://docs.gitlab.com/api/settings/

Implementation Guide

• Read the CONTRIBUTING.md guide for setting up your local development environment.
• Clone the community fork of this project.
• Add a new field called InactiveResourceAccessTokensDeleteAfterDays to the Settings and UpdateSettingsOptions in settings.go.