Update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/codetests.yml

@@ -10,7 +10,7 @@ jobs:
         os: [ubuntu, macos, windows]
     runs-on: ${{ matrix.os }}-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: actions/setup-go@v6
         with:
           go-version-file: 'go.mod'
@@ -21,7 +21,7 @@ jobs:
   codespell:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: codespell-project/actions-codespell@v2
         with:
           check_hidden: true
@@ -37,7 +37,7 @@ jobs:
     env:
       GOOS: ${{ matrix.os }}
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: actions/setup-go@v6
         with:
           go-version-file: 'go.mod'

.github/workflows/docker-publish.yml

@@ -26,7 +26,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Set up QEMU
         uses: docker/setup-qemu-action@v3