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] <[email protected]>

.github/workflows/ci.yml

@@ -17,7 +17,7 @@ jobs:
     name: Rustfmt
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - uses: dtolnay/rust-toolchain@stable
       with:
         components: rustfmt
@@ -28,7 +28,7 @@ jobs:
     name: Clippy
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - uses: dtolnay/rust-toolchain@stable
       with:
         components: clippy
@@ -43,7 +43,7 @@ jobs:
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - uses: dtolnay/rust-toolchain@stable
     - uses: Swatinem/rust-cache@v2
     - name: Run build
@@ -56,7 +56,7 @@ jobs:
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - uses: dtolnay/rust-toolchain@stable
     - uses: Swatinem/rust-cache@v2
     - name: Run tests
@@ -69,7 +69,7 @@ jobs:
   #     image: xd009642/tarpaulin
   #     options: --security-opt seccomp=unconfined
   #   steps:
-  #   - uses: actions/checkout@v3
+  #   - uses: actions/checkout@v4
   #   - name: Generate code coverage
   #     run: |
   #       cargo tarpaulin --verbose --workspace