refactors to account for large linkcheck reports

[gilzow]

What's changed

Comments in issues are limited to 65536 characters. Refactors workflow to account for cases of large broken link check reports. In those cases it will save the link report as an artifact attached to the workflow run and then create an issue with a link back to the run.

[gregqualls]

looks good to me.

[github-actions]

Your Platform.sh environment has successfully deployed. 🚀

See the site:

• Platform.sh docs
• Upsun docs

[gilzow]

Tests were failing because of

  Validating 3 new domains
  E: Error validating domain fix-link-check-ejd76ni-ucq44jg6ofare.eu-5.platformsh.site: Couldn't complete challenge [HTTP01: The client lacks sufficient authorization]
  E: Error validating domain docs.upsun.com.fix-link-check-ejd76ni-ucq44jg6ofare.eu-5.platformsh.site: Couldn't complete challenge [HTTP01: The client lacks sufficient authorization]
  Unable to validate domains fix-link-check-ejd76ni-ucq44jg6ofare.eu-5.platformsh.site, docs.upsun.com.fix-link-check-ejd76ni-ucq44jg6ofare.eu-5.platformsh.site, will retry in the background.
  Provisioned new certificate for 1 domains
  (Next refresh will be at 2025-02-13 23:07:59.268075+00:00.)
  Certificates
  - certificate d850a6b: expiring on 2025-05-14 21:59:26+00:00, covering search.fix-link-check-ejd76ni-ucq44jg6ofare.eu-5.platformsh.site

W: Missing certificate for domain fix-link-check-ejd76ni-ucq44jg6ofare.eu-5.platformsh.site
W: Missing certificate for domain docs.upsun.com.fix-link-check-ejd76ni-ucq44jg6ofare.eu-5.platformsh.site

Which is unrelated to the changes implemented into the PR