Bump actions/checkout from 3 to 4 (#591)

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]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/check_changelog.yml

@@ -15,7 +15,7 @@ jobs:
       !contains(github.event.pull_request.labels.*.name, 'dependencies')
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Check that CHANGELOG is touched
         run: |
           git fetch origin ${{ github.base_ref }} --depth 1 && \

.github/workflows/ci.yml

@@ -18,7 +18,7 @@ jobs:
     runs-on: ubuntu-22.04
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           submodules: true
       - name: Update Rust toolchain
@@ -35,7 +35,7 @@ jobs:
     runs-on: ubuntu-22.04
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           submodules: true
       - name: Update Rust toolchain
@@ -55,7 +55,7 @@ jobs:
         buildpack-directory: ${{ fromJson(needs.gather-repo-metadata.outputs.buildpack_dirs) }}
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           submodules: true
       - name: Install musl-tools
@@ -80,7 +80,7 @@ jobs:
       buildpack_dirs: ${{ steps.find-buildpack-dirs.outputs.buildpack_dirs }}
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           submodules: true
       - id: find-buildpack-dirs