Update CI for new .NET version

Author: coj337

.github/workflows/dotnet-core.yml

@@ -15,7 +15,7 @@ jobs:
     - name: Setup .NET Core
       uses: actions/setup-dotnet@v1
       with:
-        dotnet-version: 5.0.300
+        dotnet-version: 6.0.x
     - name: Install dependencies
       run: dotnet restore TheSprayer.sln
     - name: Build

.github/workflows/release.yml

@@ -27,7 +27,7 @@ jobs:
       - name: Setup dotnet
         uses: actions/setup-dotnet@v1
         with:
-          dotnet-version: 5.0.300
+          dotnet-version: 6.0.x
 
       - name: Build
         shell: bash