Abandon setup-dotnet, only rely on dev container

.github/workflows/ci.yml

@@ -7,9 +7,6 @@ on:
     branches: [ main ]
 
 env:
-  DOTNET_NOLOGO: true
-  DOTNET_CLI_TELEMETRY_OPTOUT: true
-  DOTNET_SKIP_FIRST_TIME_EXPERIENCE: true
   SYMBOL_PACKAGE: false
 jobs:
   build-and-deploy:
@@ -23,16 +20,6 @@ jobs:
       uses: actions/checkout@v3
       with:
         submodules: true
-    - name: Configure GPR
-      run: dotnet nuget add source https://nuget.pkg.github.com/sliekens/index.json --name sliekens
-    - name: Configure GPR authentication
-      uses: actions/setup-dotnet@v3
-      with:
-        source-url: https://nuget.pkg.github.com/sliekens/index.json
-        dotnet-version: ""
-        global-json-file: ""
-      env:
-        NUGET_AUTH_TOKEN: ${{secrets.GITHUB_TOKEN}}
     - name: Install dependencies
       run: dotnet restore --locked-mode
     - name: Test
@@ -52,5 +39,5 @@ jobs:
         name: packages
         path: artifacts
     - name: Upload packages to GitHub Packages
-      run: dotnet nuget push artifacts/*.nupkg --api-key ${{secrets.GITHUB_TOKEN}}
+      run: dotnet nuget push artifacts/*.nupkg --source https://nuget.pkg.github.com/sliekens/index.json --api-key ${{secrets.GITHUB_TOKEN}}
       if:  ${{ github.event_name == 'push' && github.ref == 'refs/heads/main' }}