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/ci.yml

@@ -14,7 +14,7 @@ jobs:
         toolchain: [stable, "1.60"]
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Setup Rust
         uses: dtolnay/rust-toolchain@master
         with:
@@ -28,7 +28,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Setup Rust (nightly)
         uses: dtolnay/rust-toolchain@nightly
         with:
@@ -54,7 +54,7 @@ jobs:
     continue-on-error: ${{ matrix.checks == 'advisories' }}
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Check ${{ matrix.checks }}
         uses: dnaka91/actions/deny-check@main
         with: