Migrate from AppVeyor to GitHub Actions (#1539)

* Migrate from AppVeyor to GitHub Actions

* also run on pull_request

* small formatting improvements

* add on: workflow_dispatch

this is needed to re-run jobs manually from the web UI

* Publish NuGet package to GitHub Registry

only on develop branch.

* re-add empty appveyor.yml

so it doesn't fail CI until AppVeyor integration is disabled

* fix appveyor

* typo

.github/workflows/build.yml

@@ -0,0 +1,165 @@
+name: Build
+
+on:
+  - push
+  - pull_request
+  - workflow_dispatch
+
+jobs:
+  Linux:
+    runs-on: ubuntu-24.04
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v4
+      with:
+        fetch-depth: 0 # needed for Nerdbank.GitVersioning
+
+    - name: Setup .NET
+      uses: actions/setup-dotnet@v4
+      with:
+        dotnet-version: 8.0.x
+
+    - name: Build Unit Tests .NET
+      run: dotnet build -f net8.0 test/Renci.SshNet.Tests/
+
+    - name: Build IntegrationTests .NET
+      run: dotnet build -f net8.0 test/Renci.SshNet.IntegrationTests/
+
+    - name: Build IntegrationTests .NET Framework
+      run:  dotnet build -f net48 test/Renci.SshNet.IntegrationTests/
+
+    - name: Run Unit Tests .NET
+      run: |
+        dotnet test \
+          -f net8.0 \
+          --no-build \
+          --logger "console;verbosity=normal" \
+          --logger GitHubActions \
+          -p:CollectCoverage=true \
+          -p:CoverletOutputFormat=cobertura \
+          -p:CoverletOutput=../../coverlet/linux_unit_test_net_8_coverage.xml \
+          test/Renci.SshNet.Tests/
+
+    - name: Run Integration Tests .NET
+      run: |
+        dotnet test \
+          -f net8.0 \
+          --no-build \
+          --logger "console;verbosity=normal" \
+          --logger GitHubActions \
+          -p:CollectCoverage=true \
+          -p:CoverletOutputFormat=cobertura \
+          -p:CoverletOutput=../../coverlet/linux_integration_test_net_8_coverage.xml \
+          test/Renci.SshNet.IntegrationTests/
+
+    # Also run a subset of the integration tests targeting netfx using mono. This is a temporary measure to get
+    # some coverage until a proper solution for running the .NET Framework integration tests in CI is found.
+    # Running all the tests causes problems which are not worth solving in this rare configuration.
+    # See https://github.com/sshnet/SSH.NET/pull/1462 and related links
+    - name: Run Integration Tests Mono
+      run: |
+        sudo apt-get install ca-certificates gnupg
+        sudo gpg --homedir /tmp --no-default-keyring --keyring /usr/share/keyrings/mono-official-archive-keyring.gpg --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 3FA7E0328081BFF6A14DA29AA6A19B38D3D831EF
+        echo "deb [signed-by=/usr/share/keyrings/mono-official-archive-keyring.gpg] https://download.mono-project.com/repo/ubuntu stable-focal main" | sudo tee /etc/apt/sources.list.d/mono-official-stable.list
+        sudo apt-get update
+        sudo apt-get install mono-devel
+        dotnet test \
+          -f net48 \
+          --no-build \
+          --logger "console;verbosity=normal" \
+          --logger GitHubActions \
+          -p:CollectCoverage=true \
+          -p:CoverletOutputFormat=cobertura \
+          -p:CoverletOutput=../../coverlet/linux_integration_test_net_48_coverage.xml \
+          --filter "Name~Ecdh|Name~ECDsa|Name~Zlib|Name~Gcm" \
+          test/Renci.SshNet.IntegrationTests/
+
+    - name: Archive Coverlet Results
+      uses: actions/upload-artifact@v4
+      with:
+          name: Coverlet Results Linux
+          path: coverlet
+
+  Windows:
+    runs-on: windows-2022
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v4
+      with:
+        fetch-depth: 0 # needed for Nerdbank.GitVersioning
+
+    - name: Setup .NET
+      uses: actions/setup-dotnet@v4
+      with:
+        dotnet-version: 9.0.x
+
+    - name: Build Solution
+      run: dotnet build Renci.SshNet.sln
+
+    - name: Publish AOT Compatibility Test App
+      run: dotnet publish -r win-x64 /warnaserror test/Renci.SshNet.AotCompatibilityTestApp/
+
+    - name: Create NuGet Package
+      run: dotnet pack
+
+    - name: Archive NuGet Package
+      uses: actions/upload-artifact@v4
+      with:
+        name: NuGet Package
+        path: src/Renci.SshNet/bin/Release/*.*nupkg
+
+    - name: Run Unit Tests .NET
+      run: |
+        dotnet test `
+          -f net8.0 `
+          --no-build `
+          --logger "console;verbosity=normal" `
+          --logger GitHubActions `
+          -p:CollectCoverage=true `
+          -p:CoverletOutputFormat=cobertura `
+          -p:CoverletOutput=../../coverlet/windows_unit_test_net_8_coverage.xml `
+          test/Renci.SshNet.Tests/
+
+    - name: Run Unit Tests .NET Framework
+      run: |
+        dotnet test `
+          -f net462 `
+          --no-build `
+          --logger "console;verbosity=normal" `
+          --logger GitHubActions `
+          -p:CollectCoverage=true `
+          -p:CoverletOutputFormat=cobertura `
+          -p:CoverletOutput=../../coverlet/windows_unit_test_net_4_6_2_coverage.xml `
+          test/Renci.SshNet.Tests/
+
+    - name: Archive Coverlet Results
+      uses: actions/upload-artifact@v4
+      with:
+        name: Coverlet Results Windows
+        path: coverlet
+
+  Publish:
+    runs-on: ubuntu-24.04
+    if: github.ref == 'refs/heads/develop'
+    permissions:
+      packages: write
+    needs:
+      - Windows
+      - Linux
+    steps:
+      - name: Download NuGet Package
+        uses: actions/download-artifact@v4
+        with:
+          name: NuGet Package
+
+      - name: Publish to GitHub NuGet Registry
+        run: |
+          dotnet nuget add source \
+            --username $GITHUB_ACTOR \
+            --password ${{ secrets.GITHUB_TOKEN }} \
+            --store-password-in-clear-text \
+            --name github \
+            "https://nuget.pkg.github.com/$GITHUB_REPOSITORY_OWNER/index.json"
+          dotnet nuget push "*.nupkg" \
+            --source github \
+            --api-key ${{ secrets.GITHUB_TOKEN }}