fix(CI): Update to pull_request trigger

[solracsf]

Summary

Using pull_request_target can expose secrets based on a quirk in how GitHub applies permissions to forks.
See https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#pull_request_target

Even if i'm not sure this is a problem here as this Workflow applies to Dependabot, submitting the PR to review :)

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)