Update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/ci.yml

@@ -15,7 +15,7 @@ jobs:
         node-version: ['18', '20', '22']
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: pnpm/action-setup@v3
       - uses: actions/setup-node@v4
         with:

.github/workflows/plan-release.yml

@@ -20,7 +20,7 @@ jobs:
       command: ${{ steps.check-release.outputs.command }}
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
           ref: 'master'
@@ -45,7 +45,7 @@ jobs:
     if: (github.event_name == 'push' && needs.check-plan.outputs.command != 'release') || (github.event_name == 'pull_request_target' && github.event.pull_request.merged == true)
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         # We need to download lots of history so that
         # github-changelog can discover what's changed since the last release
         with:

.github/workflows/publish.yml

@@ -22,7 +22,7 @@ jobs:
       command: ${{ steps.check-release.outputs.command }}
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
           ref: 'master'
@@ -44,7 +44,7 @@ jobs:
       attestations: write
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: pnpm/action-setup@v4
       - uses: actions/setup-node@v4
         with: