Preview build bot enhancements

[Gudahtt]

The preview build bot could use a few usability enhancements:

• Post a message in the PR when it fails
  • This was implemented in a similar workflow on the extension here
• React to the comment with a thumbs up before the build begins
  • This was implemented on a similar workflow on the extension here

[exalate-issue-sync]

Fixed by #8233.