ci: add yamllint #4

The pull request embarked with main (2dee6d8) will be merged soon

Required conditions for merge:

all of [🛡 Merge Protections rule Changelog requirements]:
- any of:
  - -title ~= ^feat
    - #4
  - label = need changelog
    - #4
  - label = skip changelog
    - #4
all of [🛡 Merge Protections rule Continuous Integration]:
- all of:
  - check-success = test (3.10)
  - check-success = test (3.11)
  - check-success = test (3.12)
  - check-success = test (3.13)
all of [🛡 Merge Protections rule Enforce conventional commit]:
- title ~= ^(fix|feat|docs|style|refactor|perf|test|build|ci|chore|revert)(?:\(.+\))?:
  - #4
all of [🛡 Merge Protections rule No review blocker]:
- #changes-requested-reviews-by = 0
  - #4
- #review-requested = 0
  - #4
- #review-threads-unresolved = 0
  - #4
all of [🛡 Merge Protections rule Reviews]:
- #approved-reviews-by >= 1
  - #4
all of [🛡 Merge Protections rule 🔎 Reviews]:
- #changes-requested-reviews-by = 0
  - #4
- #review-requested = 0
  - #4
- #review-threads-unresolved = 0
  - #4
any of [🛡 GitHub repository ruleset rule]:
- check-success = Mergify Merge Protections
- check-neutral = Mergify Merge Protections
- check-skipped = Mergify Merge Protections

Check-runs and statuses of the embarked pull request #4: