Improve the monthly release post bugs triage

Fixes a few small bugs and makes improvements to the monthly bug triage for the release post.

• Fix milestone in the issues list link, which must not have a # anymore.
• Fix the application of labels using quick action, which requires quotation marks.
• Add the ungrouped section, for bugs that were completed but are missing a specialization or group label.

Action items

• (If applicable) Add documentation to the handbook pages for Triage Operations =>
• (If applicable) Identify the affected groups and how to communicate to them:
  • /cc @person_or_group =>
  • Relevant Slack channels =>
  • Week-in-review