Update copilot-setup-steps.yml (#29863)

* Update copilot-setup-steps.yml

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

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* Update copilot-setup-steps.yml

* Update copilot-setup-steps.yml

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: mattleibow

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

@@ -8,9 +8,15 @@ jobs:
     permissions:
       contents: read
     steps:
+
       - name: Checkout code
         uses: actions/checkout@v4
 
+      - name: Setup .NET
+        uses: actions/setup-dotnet@v4
+        with:
+          dotnet-version: '9.0.x'
+
       - name: Run a pre-work build
         shell: pwsh
         run: .\build.ps1