[Investigate] notify-triagers workflow is intermittently failing

The notify-triagers workflow is behaving intermittently.

- In some runs, the workflow fails. FYR: https://github.com/asyncapi/website/actions/runs/20653553533/job/59327722596
- In other runs, it passes but still does not notify the triagers FYR: https://github.com/asyncapi/website/actions/runs/20662472045/job/59327968051?pr=4785

FYI: https://github.com/asyncapi/website/pull/4785#issuecomment-3705789821

Start with the linked failing and passing workflow runs for notify-triagers and compare their logs and notification outcomes. Trace the workflow entry point and its triager-notification steps, then verify that repeated runs both complete successfully and notify the intended triagers.

Written by the indexing model from the issue text.