Set "destroy_webhooks_before_the_project" feature flag to default

* Contributes to https://gitlab.com/gitlab-org/gitlab/-/issues/26259
* FF issue: https://gitlab.com/gitlab-org/gitlab/-/issues/328393
* Implementation MR:
https://gitlab.com/gitlab-org/gitlab/-/merge_requests/59754

changelogs/unreleased/328393_enable_destroy_webhooks_before_the_project_by_default.yml

+---
+title: Explicitly destroy webhooks and logs before the project deletion
+merge_request: 60122
+author:
+type: fixed

config/feature_flags/development/destroy_webhooks_before_the_project.yml

@@ -5,4 +5,4 @@ rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/328393
 milestone: '13.12'
 type: development
 group: group::source code
-default_enabled: false
+default_enabled: true