Apply --allow-roll-forward to install/run, see https://learn.microsoft.com/en-us/dotnet/core/whats-new/dotnet-9/sdk#net-tool-roll-forward

Author: christophwille

.github/workflows/build-ilspy.yml

@@ -28,14 +28,14 @@ jobs:
 
     - uses: actions/setup-dotnet@v4
       with:
-        dotnet-version: '8.0.x'
+        dotnet-version: '9.0.x'
         dotnet-quality: 'ga'
 
     - name: Add msbuild to PATH
       uses: microsoft/setup-msbuild@v2
 
     - name: Install dotnet-format
-      run: dotnet tool install -g dotnet-format --version "8.0.453106" --add-source https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet8/nuget/v3/index.json
+      run: dotnet tool install -g dotnet-format --allow-roll-forward --version "8.0.453106" --add-source https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet8/nuget/v3/index.json
 
     - name: Get Version
       id: version
@@ -71,7 +71,7 @@ jobs:
         paths: "test-results/${{ matrix.configuration }}.xml"
 
     - name: Format check
-      run: dotnet-format whitespace --verify-no-changes --verbosity detailed ILSpy.sln
+      run: dotnet-format whitespace --allow-roll-forward --verify-no-changes --verbosity detailed ILSpy.sln
 
     - name: Verify package contents
       if: matrix.configuration == 'debug'