Describe the bug
Using the merge_groups trigger results in an error

To Reproduce

1. Open a GitHub Action in VSCode
2. Add a trigger for merge_groups

   on:
     merge_group:
       branches: [main]

3. Observe error inline and in the Problems tab

Expected behavior
An error won't show up for this as the syntax works and is suggested by the docs for merge groups

Screenshots

Extension Version
v0.25.2