Trigger webhook on delete release event

What does this MR do and why?

Currently, we trigger webhook on release create and update events.

This merge request allows triggering webhook on the release delete event.

Changelog: changed

Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other merge requests.

Before	After
	Screen Recording 2023-10-11 at 16.51.01.mov

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

1. Have runner up
2. Open the project go to Code > Tags and create a tag
3. Open https://webhook.site/ and copy POST link
4. Go to Settings > Webhooks > click Add new webhook button
5. Put the copied link to the URL field
6. Select Releases events in the Trigger section
7. Notice the description for Releases events states "A release is created, updated."
8. Click the Add webhook button
9. Go to Deploy > Releases and create a release
10. Check the page on https://webhook.site/ --> you should get a request with {"action": "create"}
11. Go and delete the release
12. Check the page on https://webhook.site/ --> you should not get any request
13. Checkout to branch with changes
14. Go to Deploy > Releases and create a release
15. Check the page on https://webhook.site/ --> you should get a request with {"action": "create"}
16. Go and delete the release
17. Check the page on https://webhook.site/ --> you should get a request with {"action": "delete"}
18. Go to Settings > Webhooks > click Add new webhook button
19. Notice the description for Releases events now states "A release is created, updated, or deleted."

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #418113 (closed)