chore(deps): bump actions/checkout from 5.0.1 to 6.0.0

Bumps [actions/checkout](https://github.com/actions/checkout) from 5.0.1 to 6.0.0.
- [Release notes](https://github.com/actions/checkout/releases)
- [Commits](actions/checkout@v5.0.1...v6)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: 6.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

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

@@ -26,7 +26,7 @@ jobs:
     # If you do not check out your code, Copilot will do this for you.
     steps:
       - name: Checkout code
-        uses: actions/checkout@v5.0.1
+        uses: actions/checkout@v6.0.0
 
       - name: Setup .NET 9.x
         uses: actions/setup-dotnet@v5

.github/workflows/dotnet-build.yml

@@ -20,7 +20,7 @@ jobs:
           - dotnet-version: 9.x
             framework: net9.0
     steps:
-      - uses: actions/checkout@v5.0.1
+      - uses: actions/checkout@v6.0.0
       - name: Setup .NET 9.x
         uses: actions/setup-dotnet@v5
         with:
@@ -40,7 +40,7 @@ jobs:
   buildSamples:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5.0.1
+      - uses: actions/checkout@v6.0.0
       - name: Setup .NET 9.x
         uses: actions/setup-dotnet@v5
         with: