Bump actions/checkout from 2 to 4 (#14)

Bumps [actions/checkout](https://github.com/actions/checkout) from 2 to 4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v2...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/cackle.yml

@@ -11,7 +11,7 @@ jobs:
     name: cackle check and test
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@stable
       - uses: cackle-rs/cackle-action@latest
       - name: Install libpam-dev

.github/workflows/devskim.yml

@@ -18,7 +18,7 @@ jobs:
       security-events: write
     steps:
       - name: Checkout code
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Run DevSkim scanner
         uses: microsoft/DevSkim-Action@v1

.github/workflows/docker-image.yml

@@ -13,6 +13,6 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Build the Docker image
       run: docker build . --file Containerfile --tag pam-auth-test:$(date +%s)

.github/workflows/rust-clippy.yml

@@ -17,7 +17,7 @@ jobs:
       actions: read # only required for a private repository by github/codeql-action/upload-sarif to get the Action run status
     steps:
       - name: Checkout code
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
 
       - name: Install Rust toolchain
         uses: actions-rs/toolchain@16499b5e05bf2e26879000db0c1d13f7e13fa3af #@v1