Update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/merge.yml

@@ -21,7 +21,7 @@ jobs:
     if: github.event.pull_request.merged == true
     steps:
       - name: Check out committed code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Get Package Version from pyproject.toml
         id: get_version
         run: |
@@ -61,7 +61,7 @@ jobs:
       id-token: write
     steps:
       - name: Check out committed code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Prepare uv
         run: |
           pip install uv
@@ -85,7 +85,7 @@ jobs:
       contents: write
     steps:
       - name: Check out committed code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Create release tag
         id: tag_release
         uses: actions/github-script@v8

.github/workflows/verify.yml

@@ -20,7 +20,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Check out committed code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Run ShellCheck
         uses: ludeeus/action-shellcheck@master
 
@@ -29,7 +29,7 @@ jobs:
     name: Ruff check and force
     steps:
       - name: Check out committed code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           persist-credentials: false
       - name: Use python
@@ -65,7 +65,7 @@ jobs:
       - ruff
     steps:
       - name: Check out committed code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Use python
         uses: actions/setup-python@v6
         with:
@@ -93,7 +93,7 @@ jobs:
         python-version: ["3.13", "3.14"]
     steps:
       - name: Check out committed code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Use python ${{matrix.python-version}}
         uses: actions/setup-python@v6
         with:
@@ -124,7 +124,7 @@ jobs:
       - pytest
     steps:
       - name: Check out committed code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           persist-credentials: false
       - name: Use python
@@ -152,7 +152,7 @@ jobs:
       - mypy
     steps:
       - name: Check out committed code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Use python
         uses: actions/setup-python@v6
         with:
@@ -192,7 +192,7 @@ jobs:
       # - mypy
     steps:
       - name: Check out committed code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Use python
         uses: actions/setup-python@v6
         with:
@@ -237,7 +237,7 @@ jobs:
       - coverage
     steps:
       - name: Check out committed code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Use python
         uses: actions/setup-python@v6
         with: