ci: 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](https://github.com/actions/checkout/compare/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>

.github/workflows/cd-production.yml

@@ -60,7 +60,7 @@ jobs:
           echo "✅ Deploying from main branch"
 
       - name: Check recent commits
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           fetch-depth: 10
 
@@ -146,7 +146,7 @@ jobs:
       url: https://api.manacore.app
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Setup SSH
         uses: webfactory/ssh-agent@v0.9.0

.github/workflows/cd-staging-tagged.yml

@@ -206,7 +206,7 @@ jobs:
       matrix: ${{ fromJSON(needs.parse-deployment.outputs.matrix) }}
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Check Dockerfile exists
         id: check
@@ -279,7 +279,7 @@ jobs:
       url: https://staging.manacore.app
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Setup SSH
         uses: webfactory/ssh-agent@v0.9.0

.github/workflows/cd-staging.yml

@@ -52,7 +52,7 @@ jobs:
       url: https://staging.manacore.app
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Setup SSH for deployment
         uses: webfactory/ssh-agent@v0.9.0

.github/workflows/ci.yml

@@ -35,7 +35,7 @@ jobs:
     if: github.event_name == 'pull_request'
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Setup pnpm
         uses: pnpm/action-setup@v2
@@ -85,7 +85,7 @@ jobs:
       fail-fast: false
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3

.github/workflows/daily-tests.yml

@@ -70,7 +70,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Setup pnpm
         uses: pnpm/action-setup@v2
@@ -164,7 +164,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Setup pnpm
         uses: pnpm/action-setup@v2
@@ -223,7 +223,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Download coverage summary
         uses: actions/download-artifact@v4

.github/workflows/staging-config-check.yml

@@ -11,7 +11,7 @@ jobs:
     name: Validate Staging URLs
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Check for HTTP IP addresses in _CLIENT URLs
         run: |