Update release month

[ffaf1]

Include the following checklist in your PR:

• Patches conform to the coding conventions.
• N/A Is this a PR that fixes CI? If so, it will need to be backported to older cabal release branches (ask maintainers for directions).

This is cherry-picked in #11333. can be backported to master when #11333 is merged.

[mergify]

Merge Queue Status

✅ The pull request has been merged at 6b0ed65

This pull request spent 11 minutes 24 seconds in the queue, with no time running CI.
The checks were run in-place.

Required conditions to merge

• #approved-reviews-by >= 1 [🛡 GitHub branch protection]
  • Update release month #11334
• #changes-requested-reviews-by = 0 [🛡 GitHub branch protection]
  • Update release month #11334
• #review-threads-unresolved = 0 [🛡 GitHub branch protection]
  • Update release month #11334
• any of [🛡 GitHub branch protection]:
  • check-success = Doctest Cabal
  • check-neutral = Doctest Cabal
  • check-skipped = Doctest Cabal
• any of [🛡 GitHub branch protection]:
  • check-success = Meta checks
  • check-neutral = Meta checks
  • check-skipped = Meta checks
• any of [🛡 GitHub branch protection]:
  • check-success = Validate post job
  • check-neutral = Validate post job
  • check-skipped = Validate post job
• any of [🛡 GitHub branch protection]:
  • check-success = docs/readthedocs.org:cabal
  • check-neutral = docs/readthedocs.org:cabal
  • check-skipped = docs/readthedocs.org:cabal
• any of [🛡 GitHub branch protection]:
  • check-success = Bootstrap post job
  • check-neutral = Bootstrap post job
  • check-skipped = Bootstrap post job
• any of [🛡 GitHub branch protection]:
  • check-success = whitespace
  • check-neutral = whitespace
  • check-skipped = whitespace