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](https://github.com/actions/checkout/compare/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] <support@github.com>

.github/workflows/calibreapp-image-actions.yml

@@ -16,7 +16,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout Repo
-        uses: actions/checkout@v3.6.0
+        uses: actions/checkout@v4.0.0
 
       - name: Compress Images
         uses: calibreapp/image-actions@1.1.0 # TODO: if they start using a tag like v1, switch to that

.github/workflows/ci.yml

@@ -17,7 +17,7 @@ jobs:
   test:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3.6.0
+      - uses: actions/checkout@v4.0.0
         with:
           fetch-depth: 0
 

.github/workflows/codespell.yml

@@ -10,7 +10,7 @@ jobs:
     steps:
     -
       name: Checkout repository
-      uses: actions/checkout@v3.6.0
+      uses: actions/checkout@v4.0.0
     -
       name: Spell-Checking
       uses: codespell-project/actions-codespell@master

.github/workflows/editorconfig-checker.yml

@@ -9,6 +9,6 @@ jobs:
     name: editorconfig-checker
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3.6.0
+      - uses: actions/checkout@v4.0.0
       - uses: editorconfig-checker/action-editorconfig-checker@main
       - run: editorconfig-checker --exclude MathJax-es5