Bump actions/checkout from 5 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 5 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v5...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/azure-bicep-validate.yaml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Azure CLI script
         uses: azure/CLI@v2

.github/workflows/azure-dev.yaml

@@ -24,7 +24,7 @@ jobs:
       AZURE_CREDENTIALS: ${{ secrets.AZURE_CREDENTIALS }}
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Install azd
         uses: Azure/setup-azd@v2.2.0

.github/workflows/python-check.yaml

@@ -16,7 +16,7 @@ jobs:
         os: ["ubuntu-latest"]
         python_version: ["3.11"]
     steps:
-        - uses: actions/checkout@v5
+        - uses: actions/checkout@v6
         - name: Setup python
           uses: actions/setup-python@v5
           with: