Update betarelease.yml

Author: maxijabase

.github/workflows/betarelease.yml

@@ -30,14 +30,14 @@ jobs:
       - name: Install .NET Core
         uses: actions/setup-dotnet@v1
         with:
-          dotnet-version: 6.0.100
+          dotnet-version: 7.0.300
 
       # Nuget
       - name: Restore NuGet packages 
         uses: nuget/setup-nuget@v1
         with:
           nuget-version: '5.x'
-      - run: nuget restore Spcode.sln
+      - run: nuget install MahApps.Metro -Version 1.6.5 && nuget restore Spcode.sln
 
       # Setup MSBuild
       - name: Setup MSBuild