ci(deps): 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/dependencies.yml

@@ -10,7 +10,7 @@ jobs:
   check-updates:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Set up Python
         uses: actions/setup-python@v5

.github/workflows/pyqual-ci.yml

@@ -23,7 +23,7 @@ jobs:
 
     steps:
     - name: Checkout
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
       with: 
         fetch-depth: 0
         token: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/pyqual-enhanced.yml

@@ -38,7 +38,7 @@ jobs:
 
     steps:
     - name: Checkout code
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
       with:
         fetch-depth: 0  # Full history for better analysis
 
@@ -268,7 +268,7 @@ jobs:
 
     steps:
     - name: Checkout dashboard repo
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
       with:
         repository: ${{ secrets.DASHBOARD_REPO || 'your-org/pyqual-dashboard' }}
         token: ${{ secrets.DASHBOARD_TOKEN || github.token }}

.github/workflows/pyqual.yml

@@ -5,7 +5,7 @@ jobs:
   quality-loop:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
       with: {fetch-depth: 0}
 
     - uses: actions/setup-python@v5