Bump actions/checkout from 3.6.0 to 4.0.0

Bumps [actions/checkout](https://github.com/actions/checkout) from 3.6.0 to 4.0.0.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v3.6.0...v4.0.0)

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

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

.github/workflows/hugo-deploy.yml

@@ -10,7 +10,7 @@ jobs:
     if: github.repository_owner == 'brainhackorg'
     runs-on: ubuntu-20.04
     steps:
-      - uses: actions/checkout@v3.6.0
+      - uses: actions/checkout@v4.0.0
         with:
           submodules: true  # Fetch Hugo themes (true OR recursive)
           fetch-depth: 0    # Fetch all history for .GitInfo and .Lastmod

.github/workflows/issue-to-page.yml

@@ -9,7 +9,7 @@ jobs:
     if: github.repository_owner == 'brainhackorg'
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3.6.0
+    - uses: actions/checkout@v4.0.0
     - name: Set up Python
       uses: actions/setup-python@v4
       with: