Bump actions/checkout from 2 to 4

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]>

.github/workflows/auto-approve-pr.yml

@@ -18,7 +18,7 @@ jobs:
 
     steps:
       - name: Checkout PR code
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
       - run: |
           git fetch --no-tags --prune --depth=1 origin +refs/heads/*:refs/remotes/origin/*
       - name: Run git diff against repository

.github/workflows/dependency-review.yml

@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout Repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Dependency Review
         uses: actions/dependency-review-action@v2
         with:

.github/workflows/format-code.yml

@@ -8,7 +8,7 @@ jobs:
   format-code:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: ministryofjustice/github-actions/code-formatter@v7
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/link-checker.yml

@@ -10,7 +10,7 @@ jobs:
   linkChecker:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
 
       - name: Link Checker
         uses: lycheeverse/[email protected]

.github/workflows/publish.yml

@@ -13,7 +13,7 @@ jobs:
       image: ministryofjustice/tech-docs-github-pages-publisher:v3.0.2
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Compile Markdown to HTML and create artifact
         run: |
           cd runbooks; /scripts/deploy.sh false