fix(ci): update dotnet-version from 9.x to 10.x to match global.json (#141)

global.json requires SDK 10.0.103 with rollForward: latestFeature,
but the workflow only installed .NET 9.x. The runner's pre-installed
10.0.102 didn't satisfy the minimum version requirement, causing
`dotnet restore` to fail with "A compatible .NET SDK was not found."

Author: phmatray

.github/workflows/dotnet.yml

@@ -21,7 +21,7 @@ jobs:
     - name: Setup .NET
       uses: actions/setup-dotnet@v5
       with:
-        dotnet-version: 9.x
+        dotnet-version: 10.x
 
     - name: Restore dependencies
       run: dotnet restore