Bump the github-actions group with 1 update

Bumps the github-actions group with 1 update: [actions/checkout](https://github.com/actions/checkout).


Updates `actions/checkout` from 4.1.1 to 4.1.2
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@b4ffde6...9bb5618)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: github-actions
...

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/validation.yml

@@ -13,6 +13,6 @@ jobs:
     name: Validate against TEI_all
     steps:
       - name: Checkout
-        uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
+        uses: actions/checkout@9bb56186c3b09b4f86b1c65136769dd318469633 # v4.1.2
       - name: Validate
         uses: dracor-org/tei-validate-action@94b08b8bf0dd1810fe7962aa59435b46c769bbcb # v1.2.0