build(deps): bump actions/checkout from 5 to 6 (#3035)

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]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/release-please-gha.yml

@@ -19,7 +19,7 @@ jobs:
   release:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Generate GitHub App token
         id: app-token

.github/workflows/release-please.yml

@@ -19,7 +19,7 @@ jobs:
   release:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Generate GitHub App token
         id: app-token

.github/workflows/validatePublicAPISurface.yml

@@ -16,7 +16,7 @@ jobs:
   validate-public-api-surface:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: microsoftgraph/kiota-dom-export-diff-tool/export@main
         id: generatePatch
       - uses: microsoftgraph/kiota-dom-export-diff-tool/tool@main

.github/workflows/validatePullRequest.yml

@@ -18,7 +18,7 @@ jobs:
     env:
       solutionName: Microsoft.Graph.sln
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Setup .NET
         uses: actions/[email protected]
         with: