Notify Figma library maintainers on release

[dgtlntv]

As part of my efforts for creating a new Figma library I have added a script to the webteam bot which can be used to alert Figma library maintainers in the ~Figma library maintainers chat of changes of sources of truth. Amongst those sources of truth we need to keep track of to keep the Figma libraries up to date is of course Vanilla CSS.
This PR adds a job to the Github action that is triggered on release of a new Vanilla version and sends the sections 🚀 Features, 🐛 Bug Fixes and 🔨 Maintenance of the release notes as an alert to the bot to notify Figma library maintainers of the changes to Vanilla CSS

Additionally to these changes we would need to add the chat bots URL to the action secrets of the repository.

Fixes: WD-12092

Done

• Add job to release action to notify Figma library maintainers

QA

• I am not aware of a good way of QAing Github actions other than in production.

[webteam-app]

Demo

Jenkins

demos.haus

[jmuzina]

I think this is looking good. Where do we get the chat bot URL?

[bartaz]

I think this is looking good. Where do we get the chat bot URL?

I got it from Max and added to repo, so it should be all set for next release.

[bartaz]

Looks good, thanks.

On the next release we will see how it works and if it needs any adjustments.