Upgraded GitHub CI to use .NET 6

Author: dustinmoris

.github/workflows/build.yml

@@ -19,7 +19,7 @@ jobs:
       - name: Setup .NET Core
         uses: actions/setup-dotnet@v1
         with:
-          dotnet-version: 5.0.100
+          dotnet-version: 6.0.301
 
       - name: Restore
         run: dotnet restore
@@ -58,4 +58,4 @@ jobs:
           PATTERN="refs/tags/v"
           SUB=""
           TAG="${GITHUB_REF/$PATTERN/$SUB}"
-          docker push $PROJECT/$IMAGE:$TAG
+          docker push $PROJECT/$IMAGE:$TAG