Update gitlab-org-contribution to 0.8.1

Update skill: gitlab-org-contribution 0.8.1

Description

Brings skills/gitlab-org-contribution/ to release 0.8.1 of the skill. I took !214 (merged) back into my repository first, so its undercoverage entry is unchanged here and 0.8.1 is above both versions. What changes for readers:

• To-Do List. A new section in references/troubleshooting.md explains why a contributor's To-Do badge keeps growing (a merge or close resolves only a few kinds of To-Do, and nothing clears the rest later), which To-Dos are settled and may be marked done, which never are, and how to list, mark and restore them. Step 17 of SKILL.md, review.md, workflow.md and bots.md point to it.
• Contributor platform. review.md and hackathon-and-platform.md describe the deployed Request review page: it ticks nobody when the MR already has other reviewers, and its note with Duo asks the author to handle Duo's feedback first.
• Re-requesting review. The sidebar's Re-request review button now shows for an author without a role, and Duo's new review is requested after the push that answers it.
• Smaller corrections: push notes, approvals a push keeps or removes in gitlab-org/gitlab, the %{first_commit} squash template, split MRs, the documentation reviewer automation on generated doc/ files, and an anonymous git fetch refused under load.

The copy is still SKILL.md and references/ only, and SKILL.md stays at 93 lines. The rest of the diff is what bin/distribute-skill and lefthook run auto-fix generate.

Checklist

• Bumped version in SKILL.md from 0.7.2 to 0.8.1
• Ran bin/distribute-skill to update the plugin's version
• Ran lefthook run auto-fix to update docs and manifests
• All CI jobs pass

Checks run before pushing

• bin/ci-checks, the lefthook pre-push hook and the verify and lint jobs as .gitlab-ci.yml writes them on main at 406eeac9, in python:3.12-alpine3.20, and test-skill-hooks-plugin in node:22-alpine: all pass. Content quality reports no broken link and no warning for this skill.
• diff -r between the v0.8.1 tag's skills/gitlab-org-contribution/ and this copy shows the same paths left out and the same four SKILL.md edits as for the 0.7.1 copy, nothing else.
• The read-only commands the new To-Do section gives, run against gitlab.com: the REST list and its filters answer, currentUserTodos gives the same count as the REST list, and todoResolveMany, todosMarkAllDone and todoRestoreMany exist in the live schema with the arguments the section uses (not run).