Bump actions/checkout from 5 to 6 in /.github/workflows

Bumps [actions/checkout](https://github.com/actions/checkout) from 5 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v5...v6)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/docker-branch.yml

@@ -33,7 +33,7 @@ jobs:
         tags: |
           type=ref,event=branch,prefix=branch-
 
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
 
     - name: Test
       run: echo "ghcr.io/${{ env.REPO_LOWER }}:branch-${GITHUB_REF##*/}"

.github/workflows/publish.yml

@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Check out the repo
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Determine Short SHA
         run: echo ${{ github.sha }} | tail -c 8 | (read; echo SHORT_SHA=$REPLY) >> $GITHUB_ENV

.github/workflows/publish_dx.yml

@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Check out the repo
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Sanitize Version for Tagging
         run: echo ${{ github.event.release.tag_name }} | sed 's/^v//' | (read; echo SHORT_VERSION=$REPLY) >> $GITHUB_ENV