Bump actions/checkout from 5 to 6 in the actions group (#164)

Author: dependabot[bot]

.github/workflows/cleanup-pr-preview.yml

@@ -10,7 +10,7 @@ jobs:
     permissions:
       contents: write
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           ref: gh-pages
       - run: git config user.name "github-actions[bot]"

.github/workflows/lint.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           persist-credentials: false
       - uses: actions/setup-python@v6

.github/workflows/run-tests.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           persist-credentials: false
       - uses: actions/setup-python@v6

.github/workflows/update.yml

@@ -17,7 +17,7 @@ jobs:
         with:
           python-version: "3.x"
       - uses: astral-sh/setup-uv@v7
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - run: sudo apt-get install -y gettext
       - run: pip install -r requirements.txt
       - run: uv run generate.py  # generates index.html and index.json