Run the distro validation script daily

[Blue (OneBlue)]

Summary of the Pull Request

This change updates the distro validation workflow to run daily. Once done, we'll probably need another job to check its result and notify us for failures

PR Checklist

• Closes: Link to issue #xxx
• Communication: I've discussed this with core contributors already. If work hasn't been agreed, this work might be rejected
• Tests: Added/updated if needed and all pass
• Localization: All end user facing strings can be localized
• Dev docs: Added/updated if needed
• Documentation updated: If checked, please file a pull request on our docs repo and link it here: #xxx

Detailed Description of the Pull Request / Additional comments

Validation Steps Performed

[Copilot]

Pull request overview

This PR updates the existing GitHub Actions workflow that validates distribution metadata so it also runs automatically on a daily schedule (in addition to PRs that touch distributions/**). This helps catch regressions or upstream changes even when no relevant PR is opened.

Changes:

• Add a schedule trigger to run the workflow daily at 00:00 (UTC).
• Keep the existing pull_request trigger scoped to distributions/**.