chore: Update required CI check names in branch protection

[schloerke]

The branch protection rules reference CI check names that may be outdated or incomplete. During the v0.10.8 assets bump (#177), R-CMD-check / ubuntu-latest (4.5.3) was stuck pending and blocked the merge, even though all other R-CMD-check variants passed.

Action items:

• Review the required status checks in the main branch protection settings
• Ensure the required check names match the current CI workflow job names
• Consider whether the integration job should be required (it currently fails due to an unrelated issue)

🤖 Generated with Claude Code

[schloerke]

Removed check requirements as they are moving targets