build(deps): bump actions/checkout from 3 to 4

Bumps [actions/checkout](https://github.com/actions/checkout) from 3 to 4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v3...v4)

---
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/fmt.yml

@@ -27,7 +27,7 @@ jobs:
   check-code-formatting:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: "Install Rust"
       uses: dtolnay/rust-toolchain@stable
       with:

.github/workflows/make-release.yml

@@ -12,7 +12,7 @@ jobs:
       contents: write
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Generate Changelog
         run: echo "See https://docs.kumomta.com/changelog/${{ github.ref_name }}" > ${{ github.workspace }}-CHANGELOG.txt
       - name: Make Release

.github/workflows/publish-pkg-repos.yml

@@ -15,7 +15,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: "Publish"
       if: ${{ github.ref == 'refs/heads/main' }}
       env: