Update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/docker.yaml

@@ -17,7 +17,7 @@ jobs:
       packages: write
     steps:
       - name: checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3

.github/workflows/format.yaml

@@ -11,7 +11,7 @@ jobs:
     name: black
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
     - uses: actions/setup-python@v6
       with:
         python-version: "3.x"

.github/workflows/pip.yaml

@@ -15,7 +15,7 @@ jobs:
         python-version: ["3.11"]
     runs-on: ${{ matrix.os }}
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
     - uses: actions/setup-python@v6
       with:
         python-version: ${{ matrix.python-version }}

.github/workflows/pypi.yaml

@@ -14,7 +14,7 @@ jobs:
     name: Build SDist
     runs-on: ubuntu-24.04
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
     - name: Build SDist
       run: pipx run build --sdist
     - name: Check metadata

.github/workflows/test.yaml

@@ -11,7 +11,7 @@ jobs:
     name: test
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
     - uses: actions/setup-python@v6
       with:
         python-version: "3.x"