⬆️ 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/continuous-deployment.yml

@@ -15,7 +15,7 @@ jobs:
     steps:
       - id: checkout
         name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - id: check-ruff
         name: Check with Ruff
@@ -37,7 +37,7 @@ jobs:
     steps:
       - id: checkout
         name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - id: install-uv
         name: Install uv
@@ -67,7 +67,7 @@ jobs:
         python: ['3.10', '3.11', '3.12', '3.13']
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - id: install-uv
         name: Install uv
@@ -97,7 +97,7 @@ jobs:
     needs: [test-python]
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - id: install-uv
         name: Install uv