Fix client build

.github/workflows/main.yml

@@ -22,7 +22,7 @@ jobs:
         with:
           submodules: true
       - name: Setup MSBuild.exe
-        uses: warrenbuckley/Setup-MSBuild@v1
+        uses: microsoft/setup-msbuild@v1.0.1
       - name: Setup .NET Core
         uses: actions/setup-dotnet@v1
         with:
@@ -30,7 +30,7 @@ jobs:
       - name: Install dependencies
         run: dotnet restore ./src
       - name: Build Impostor.Client
-        run: msbuild ./src/Impostor.Client/Impostor.Client.csproj /p:Configuration=Release
+        run: dotnet msbuild ./src/Impostor.Client/Impostor.Client.csproj /p:Configuration=Release
       - name: Build Impostor.Server
         run: dotnet build --no-restore -c Release -f netcoreapp3.1 ./src/Impostor.Server/Impostor.Server.csproj /p:PublishTrimmed=false
       - name: Test