fix: github action canceling valid tasks for checking semantic pr title (#3127)

# What does this PR do?
<!-- Provide a short summary of what this PR does and why. Link to
relevant issues if applicable. -->
This PR changes the group name from github.ref to
github.even.pull_request_number. The reason for this is that github.ref
does not act as a unique identifier in the pull_request_target event and
only is unique in pull_request. The github action was getting canceled
was because the group name was not unique in the concurrency section.

<!-- If resolving an issue, uncomment and update the line below -->
Closes #3102

## Test Plan
<!-- Describe the tests you ran to verify your changes with result
summaries. *Provide clear instructions so the plan can be easily
re-executed.* -->
To test this I have created a fake github action and ran it trough act
to see what the github.ref variable produced and what alternatives can
be used. This confirmed that the github.ref was not unique and that
github.event.pull_request_number is unique to the PR.

.github/workflows/semantic-pr.yml

@@ -11,7 +11,7 @@ on:
       - synchronize
 
 concurrency:
-  group: ${{ github.workflow }}-${{ github.ref }}
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number }}
   cancel-in-progress: true
 
 permissions: