Bump actions/checkout from 4 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 4 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v4...v6)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/accessibility_tests.yml

@@ -16,7 +16,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Prepare application environment
         uses: ./.github/actions/prepare-app-env
@@ -85,7 +85,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Prepare application environment
         uses: ./.github/actions/prepare-app-env

.github/workflows/backup_db.yml

@@ -45,7 +45,7 @@ jobs:
       BACKUP_FILE: ${{ inputs.backup-file || 'schedule'  }}
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - uses: azure/login@v2
         with:

.github/workflows/backup_production_db.yml

@@ -26,7 +26,7 @@ jobs:
         options: --health-cmd pg_isready --health-interval 10s --health-timeout 5s --health-retries 5
     steps:
     - name: Checkout code
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
 
     - name: Configure AWS credentials
       uses: aws-actions/configure-aws-credentials@v5

.github/workflows/build_and_deploy.yml

@@ -52,7 +52,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Cache swagger docs
         uses: actions/cache@v5
@@ -88,7 +88,7 @@ jobs:
 
     steps:
 
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         name: Checkout Code
 
       - name: Configure AWS credentials
@@ -241,7 +241,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       name: Checkout Code
 
     - name: Configure AWS credentials
@@ -344,7 +344,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         name: Checkout Code
 
       - name: Set environment variables from build output

.github/workflows/delete_review_app.yml

@@ -70,7 +70,7 @@ jobs:
       with:
         parameterPairs: "/teaching-vacancies/github_action/infra/slack_webhook = SLACK_WEBHOOK"
 
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       name: Checkout Code
 
     - uses: google-github-actions/auth@v3

.github/workflows/deploy_app_via_workflow_dispatch.yml

@@ -27,7 +27,7 @@ jobs:
 
     steps:
     - name: Checkout code
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
 
     - name: Deploy App to ${{ inputs.environment }} environment
       uses: ./.github/actions/deploy/

.github/workflows/lint.yml

@@ -14,7 +14,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Prepare application environment
         uses: ./.github/actions/prepare-app-env
@@ -37,7 +37,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Prepare application environment
         uses: ./.github/actions/prepare-app-env
@@ -54,7 +54,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Terraform pin version
         uses: hashicorp/setup-terraform@v3
@@ -88,7 +88,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Prepare application environment
         uses: ./.github/actions/prepare-app-env

.github/workflows/maintenance.yml

@@ -30,7 +30,7 @@ jobs:
 
     steps:
     - name: Checkout
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
 
     - name: Enable or disable maintenance mode
       uses: DFE-Digital/github-actions/maintenance@master

.github/workflows/postgres-recover-deleted-db.yml

@@ -45,7 +45,7 @@ jobs:
     concurrency: deploy_${{ inputs.environment }}
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Set environment variables
         run: |

.github/workflows/rebuild_docker_cache.yml

@@ -18,7 +18,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         name: Checkout Code
 
       - name: Configure AWS credentials