chore(ci): skip check-pr-tag job if not PR

[legobeat]

Description

Skip check-pr-tag job when there is no associated PR.

Fix failing CI check on develop.

Related issues

• Follow-up to #24193

Manual testing steps

Screenshots/Recordings

Before

After

Pre-merge author checklist

• [x] I’ve followed MetaMask Coding Standards.
• [x] I've completed the PR template to the best of my ability
• [x] I’ve included tests if applicable
• [x] I’ve documented my code using JSDoc format if applicable
• [x] I’ve applied the right labels on the PR (see labeling guidelines). Not required for external contributors.

Pre-merge reviewer checklist

• [ ] I've manually tested the PR (e.g. pull and build branch, run the app, test code being changed).
• [ ] I confirm that this PR addresses all acceptance criteria described in the ticket it closes and includes the necessary testing evidence such as recordings and or screenshots.

[github-actions[bot]]

CLA Signature Action: All authors have signed the CLA. You may need to manually re-run the blocking PR check if it doesn't pass in a few minutes.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 67.36%. Comparing base (d27a233) to head (6f61583). Report is 37 commits behind head on develop.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## develop #24379 +/- ## =========================================== - Coverage 67.37% 67.36% -0.01% =========================================== Files 1278 1286 +8 Lines 49881 50117 +236 Branches 12944 13005 +61 =========================================== + Hits 33605 33760 +155 - Misses 16276 16357 +81 ```

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