Move auto_disabling_web_hooks FF to setting
<!--IssueSummary start-->
<details>
<summary>
Everyone can contribute. [Help move this issue forward](https://handbook.gitlab.com/handbook/marketing/developer-relations/contributor-success/community-contributors-workflows/#contributor-links) while earning points, leveling up and collecting rewards.
</summary>
- [Work on this issue](https://contributors.gitlab.com/manage-issue?action=work&projectId=278964&issueIid=527754)
- [Close this issue](https://contributors.gitlab.com/manage-issue?action=close&projectId=278964&issueIid=527754)
</details>
<!--IssueSummary end-->
### Proposal
This is related to https://gitlab.com/groups/gitlab-org/-/epics/17281. As part of an [Engineering-wide effort](https://gitlab.com/groups/gitlab-org/-/epics/15814) we want to clean up feature flags in areas where possible. Feature flags are not supported on Dedicated and therefore those features cannot be utilized by customers on the Dedicated platform.
Part of this is the `auto_disabling_web_hooks` flag. Let's move the functionality that is behind this feature flag to a new application setting in `Settings > General` - add there a new **Webhooks** section.
Coordinate with ~"group::organizations", since we're looking to move most of the settings out of Admin Area to Organizations.
See application settings developer docs https://docs.gitlab.com/development/application_settings/.
We would update the ~documentation:
- [Application settings API documentation](https://gitlab.com/gitlab-org/gitlab/-/blob/6f33ad46ffeac454c6c9ce92d6ba328a72f062fd/doc/api/settings.md)
- [Auto-disabled webhooks documentation](https://docs.gitlab.com/user/project/integrations/webhooks/#auto-disabled-webhooks )
- GitLab admin settings (something under [here](https://docs.gitlab.com/administration/settings/))
issue