update CI

Author: xorus

.github/workflows/build.yml

@@ -24,7 +24,7 @@ jobs:
       - name: Setup .NET
         uses: actions/setup-dotnet@v4
         with:
-          dotnet-version: 8.0.*
+          dotnet-version: 9.0.*
       - name: Restore dependencies
         run: dotnet restore
       - name: Download Dalamud