build(deps): bump actions/checkout from 4 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 4 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v4...v6)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -14,7 +14,7 @@ jobs:
         os: [ubuntu-latest, macos-latest, windows-latest]
     runs-on: ${{ matrix.os }}
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: Test with Pester
         run: ./test.ps1
       - name: Invoke action
@@ -43,7 +43,7 @@ jobs:
   build-docs:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: Build module docs
         uses: ./
         with:
@@ -56,7 +56,7 @@ jobs:
         os: [ubuntu-latest, macos-latest, windows-latest]
     runs-on: ${{ matrix.os }}
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       # return string result
       - name: Test that returned result string is not json serialized (act)

.github/workflows/demo-command.yml

@@ -18,7 +18,7 @@ jobs:
         with:
           comment-id: ${{ github.event.client_payload.github.payload.comment.id }}
           body: "[Workflow run](https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }})"
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: Get script text
         uses: ./
         id: get-script-text

.github/workflows/tag-command.yml

@@ -17,7 +17,7 @@ jobs:
         with:
           comment-id: ${{ github.event.client_payload.github.payload.comment.id }}
           body: "[Workflow run](https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }})"
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           ref: ${{ github.event.client_payload.slash_command.args.named.ref }}
       - name: Resolve version, tag and push