Bump actions/checkout from 5 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 5 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v5...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] <[email protected]>

Author: dependabot[bot]

.github/workflows/CI.yml

@@ -29,7 +29,7 @@ jobs:
     runs-on: ${{ matrix.runner-os }}
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           persist-credentials: false
       - uses: extractions/setup-just@v3
@@ -115,7 +115,7 @@ jobs:
         target-os: [windows-latest, ubuntu-latest, macos-latest]
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           persist-credentials: false
       - uses: extractions/setup-just@v3
@@ -167,7 +167,7 @@ jobs:
     runs-on: ${{ matrix.runner-os }}
     concurrency: integration-test-${{ matrix.source-vcs }}-${{ matrix.runner-os }}
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           persist-credentials: false
 
@@ -301,7 +301,7 @@ jobs:
     environment: PUBLISH_RELEASE
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           token: ${{ secrets.RELEASE_NOTES_PAT }}
           fetch-depth: 0

.github/workflows/copilot-setup-steps.yml

@@ -18,7 +18,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Setup .NET
         uses: actions/setup-dotnet@v2

.github/workflows/integration-tests.yml

@@ -23,7 +23,7 @@ jobs:
         target-os: [windows-latest, ubuntu-latest, macos-latest]
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         ref: 'refs/pull/${{ github.event.inputs.pr_number }}/merge'
         fetch-depth: 0
@@ -95,7 +95,7 @@ jobs:
     runs-on: ${{ matrix.runner-os }}
     concurrency: integration-test-${{ matrix.source-vcs }}-${{ matrix.runner-os }}
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         ref: 'refs/pull/${{ github.event.inputs.pr_number }}/merge'
         fetch-depth: 0