Update actions/checkout action to v6 (#31)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/release-github.yml

@@ -12,7 +12,7 @@ jobs:
     permissions:
       contents: write
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: cucumber/[email protected]
         with:
           github-token: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/release-npm.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-latest
     environment: Release
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: actions/setup-node@v6
         with:
           node-version: '24.x'

.github/workflows/site.yml

@@ -9,7 +9,7 @@ jobs:
   upload-artifact:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: actions/setup-node@v6
         with:
           node-version: 22.x

.github/workflows/test.yml

@@ -21,7 +21,7 @@ jobs:
       fail-fast: false
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: with Node.js ${{ matrix.node-version }} on ${{ matrix.os }}
         uses: actions/setup-node@v6
         with:
@@ -35,7 +35,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: actions/setup-node@v6
         with:
           node-version: 24.x
@@ -47,7 +47,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: actions/setup-node@v6
         with:
           node-version: 24.x