Modify documentation for zoom quick action

Modifies the documentation for quick actions to remove the feature flag
and adds a changelog entry for the zoom quick actions feature

changelogs/unreleased/32133-remove-feature-flag-for-zoom.yml

+---
+title: Allow users to add and remove zoom rooms on an issue using quick action commands
+merge_request:
+author:
+type: added

doc/user/project/quick_actions.md

@@ -64,8 +64,8 @@ The following quick actions are applicable to descriptions, discussions and thre
 | `/create_merge_request <branch name>` | ✓     |               |      | Create a new merge request starting from the current issue |
 | `/relate #issue1 #issue2`             | ✓     |               |      | Mark issues as related **(STARTER)** |
 | `/move <path/to/project>`             | ✓     |               |      | Move this issue to another project |
-| `/zoom <Zoom URL>`                    | ✓     |               |      | Add Zoom meeting to this issue. ([Introduced in GitLab 12.3](https://gitlab.com/gitlab-org/gitlab/merge_requests/16609). Must be enabled by feature flag `issue_zoom_integration` for self-hosted. [Feature flag to be removed and available by default in 12.4.](https://gitlab.com/gitlab-org/gitlab/issues/32133)) |
-| `/remove_zoom`                        | ✓     |               |      | Remove Zoom meeting from this issue. ([Introduced in GitLab 12.3](https://gitlab.com/gitlab-org/gitlab/merge_requests/16609). Must be enabled by feature flag `issue_zoom_integration` for self-hosted. [Feature flag to be removed and available by default in 12.4.](https://gitlab.com/gitlab-org/gitlab/issues/32133)) |
+| `/zoom <Zoom URL>`                    | ✓     |               |      | Add Zoom meeting to this issue. |
+| `/remove_zoom`                        | ✓     |               |      | Remove Zoom meeting from this issue. |
 | `/target_branch <local branch name>`  |       | ✓             |      | Set target branch |
 | `/wip`                                |       | ✓             |      | Toggle the Work In Progress status |
 | `/approve`                            |       | ✓             |      | Approve the merge request |