Update dotnet.yml

Author: wenbinf

.github/workflows/dotnet.yml

@@ -14,9 +14,9 @@ jobs:
     steps:
     - uses: actions/checkout@v4
     - name: Setup .NET
-      uses: actions/setup-dotnet@v1
+      uses: actions/setup-dotnet@v4
       with:
-        dotnet-version: 5.0.x
+        dotnet-version: 8.0.x
     - name: Restore dependencies
       run: dotnet restore
       working-directory: src