Add issue template for feature flag cleanup

.gitlab/issue_templates/Feature Flag Cleanup.md

+<!-- Title suggestion: [Feature flag] Cleanup <feature-flag-name> -->
+
+## Summary
+
+This issue is to cleanup the `<feature-flag-name>` feature flag, after the feature flag has been enabled by default for an appropriate amount of time in production.
+
+<!-- Short description of what the feature is about and link to relevant other issues. -->
+
+## Owners
+
+- Team: NAME_OF_TEAM
+- Most appropriate slack channel to reach out to: `#g_TEAM_NAME`
+- Best individual to reach out to: NAME
+- PM: NAME
+
+## Stakeholders
+
+<!--
+Are there any other stages or teams involved that need to be kept in the loop?
+
+- Name of a PM
+- The Support Team
+- The Delivery Team
+-->
+
+## Expectations
+
+### What might happen if this goes wrong?
+
+<!-- Any MRs that need to be rolled back? Communication that needs to happen? What are some things you can think of that could go wrong - data loss or broken pages? -->
+
+### Cleaning up the feature flag
+
+<!-- The checklist here is to help stakeholders keep track of the feature flag status -->
+- [ ] Create a merge request to remove `<feature-flag-name>` feature flag. Ask for review and merge it.
+    - [ ] Remove all references to the feature flag from the codebase.
+    - [ ] Remove the YAML definitions for the feature from the repository.
+    - [ ] Create [a changelog entry](https://docs.gitlab.com/ee/development/feature_flags/#changelog).
+- [ ] Ensure that the cleanup MR has been deployed to both production and canary.
+      If the merge request was deployed before [the code cutoff](https://about.gitlab.com/handbook/engineering/releases/#self-managed-releases-1),
+      the feature can be officially announced in a release blog post.
+    - [ ] `/chatops run auto_deploy status <merge-commit-of-cleanup-mr>`
+- [ ] Close [the feature issue](ISSUE LINK) to indicate the feature will be released in the current milestone.
+- [ ] Clean up the feature flag from all environments by running these chatops command in `#production` channel:
+    - [ ] `/chatops run feature delete <feature-flag-name> --dev`
+    - [ ] `/chatops run feature delete <feature-flag-name> --staging`
+    - [ ] `/chatops run feature delete <feature-flag-name>`
+- [ ] Close this rollout issue.
+
+
+/label ~"feature flag" ~"type::feature" ~"feature::addition"
+/assign DRI

.gitlab/issue_templates/Feature Flag Roll Out.md

@@ -121,7 +121,7 @@ To do so, follow these steps:
     - [ ] `/chatops run auto_deploy status <merge-commit-of-default-enabling-mr>`
 - [ ] Close [the feature issue](ISSUE LINK) to indicate the feature will be released in the current milestone.
 - [ ] Set the next milestone to this rollout issue for scheduling [the flag removal](#release-the-feature).
-- [ ] (Optional) You can create a separate issue for scheduling the steps below to [Release the feature](#release-the-feature).
+- [ ] (Optional) You can [create a separate issue](https://gitlab.com/gitlab-org/gitlab/-/issues/new?issuable_template=Feature%20Flag%20Cleanup) for scheduling the steps below to [Release the feature](#release-the-feature).
     - [ ] Set the title to "[Feature flag] Cleanup `<feature-flag-name>`".
     - [ ] Execute the `/copy_metadata <this-rollout-issue-link>` quick action to copy the labels from this rollout issue.
     - [ ] Link this rollout issue as a related issue.
@@ -141,6 +141,8 @@ the [clean up](https://docs.gitlab.com/ee/development/feature_flags/controls.htm
 should be done as soon as possible to permanently enable the feature and reduce complexity in the
 codebase.
 
+You can either [create a follow-up issue for Feature Flag Cleanup](https://gitlab.com/gitlab-org/gitlab/-/issues/new?issuable_template=Feature%20Flag%20Cleanup) or use the checklist below in this same issue.
+
 <!-- The checklist here is to help stakeholders keep track of the feature flag status -->
 - [ ] Create a merge request to remove `<feature-flag-name>` feature flag. Ask for review and merge it.
     - [ ] Remove all references to the feature flag from the codebase.