Update actions/checkout action to v6 (#127)

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

Author: renovate[bot]

.github/workflows/plan-release.yml

@@ -21,7 +21,7 @@ jobs:
       command: ${{ steps.check-release.outputs.command }}
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
           ref: 'main'
@@ -46,7 +46,7 @@ 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@v5
+      - 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

@@ -23,7 +23,7 @@ jobs:
       command: ${{ steps.check-release.outputs.command }}
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
           ref: 'main'
@@ -43,7 +43,7 @@ jobs:
       pull-requests: write
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: actions/setup-node@v6
         with:
           node-version: 24

.github/workflows/push-dist.yml

@@ -14,7 +14,7 @@ jobs:
       contents: write
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: wyvox/action-setup-pnpm@v3
       - uses: kategengler/[email protected]
         with: