Context

If we have workflows attached with on.pull_request [labeled, unlabeled] event trigger, it runs no matter what labels are added/removed.

• This may not be the ideal scenario that the workflow may be expensive or taking long time to run, and it would be great if the labeled action can also have a label filter that get triggered.
• And many unnecessary workflows/jobs are showing as "skipped" in the UI, not a great user experience.

Proposal syntax

on:
  pull_request:
    types: [labeled, unlabeled]
    label_filter: '*' # which is the default, and we can use the same file pattern match like 'test', '*test', '*bot'

OR

on:
  pull_request:
    types: [labeled, labeled:*, unlabeled:*, labeled:*test, labeled:*bot]