Migrate from AppVeyor to GitHub Actions

[mus65]

This migrates from AppVeyor to GitHub Actions. This initially came up in #1480 (comment) because we would have to wait for AppVeyor to support .NET 9 .

I tried to keep the functionality mostly the same. I made the following changes:

• Replaced AppVeyor.TestLogger with GitHubActionsTestLogger so the test results are displayed in GitHub.
• removed LiquidTestReports.Markdown integration. This was added with Test integration tests #1250 . Not sure how useful this is considering the test results are visible in GitHub directly now. I could add it back.
• removed redundant -c and --no-restore parameters from dotnet calls
• mono must be installed manually since the runner doesn't provide it out-of-the-box.
• Upgraded AotCompatibilityTestApp to net9.0 already here since net8.0 would result in the following failure. No idea why this doesn't happen in AppVeyor.

Run dotnet publish -r win-x64 /warnaserror .\test\Renci.SshNet.AotCompatibilityTestApp\
  Determining projects to restore...
  Restored D:\a\SSH.NET\SSH.NET\test\Renci.SshNet.AotCompatibilityTestApp\Renci.SshNet.AotCompatibilityTestApp.csproj (in 357 ms).
  Restored D:\a\SSH.NET\SSH.NET\src\Renci.SshNet\Renci.SshNet.csproj (in 365 ms).
  Renci.SshNet -> D:\a\SSH.NET\SSH.NET\src\Renci.SshNet\bin\Release\net8.0\Renci.SshNet.dll
  Renci.SshNet.AotCompatibilityTestApp -> D:\a\SSH.NET\SSH.NET\test\Renci.SshNet.AotCompatibilityTestApp\bin\Release\net8.0\win-x64\Renci.SshNet.AotCompatibilityTestApp.dll
  Generating native code
Error: /_/src/libraries/System.Net.Quic/src/System/Net/Quic/Internal/MsQuicApi.cs(90): error IL3000: System.Net.Quic.MsQuicApi..cctor(): 'System.Reflection.Assembly.Location.get' always returns an empty string for assemblies embedded in a single-file app. If the path to the app directory is needed, consider calling 'System.AppContext.BaseDirectory'. [D:\a\SSH.NET\SSH.NET\test\Renci.SshNet.AotCompatibilityTestApp\Renci.SshNet.AotCompatibilityTestApp.csproj]
  Renci.SshNet.AotCompatibilityTestApp -> D:\a\SSH.NET\SSH.NET\test\Renci.SshNet.AotCompatibilityTestApp\bin\Release\net8.0\win-x64\publish\

Coverlet results are still only archived but not integrated or displayed anywhere. There is #1257 open for this. There is also some kind of GitHub Integration for this. I could look into this separately.

[mus65]

Test results and artifacts: https://github.com/sshnet/SSH.NET/actions/runs/11869304328

It still tries to run AppVeyor here. I assume this must be disabled in the project.

side note: I have not seen a single flaky test failure while testing this. 😄

[Rob-Hague]

A lot faster too. One thing I think is missing at the moment is a CI nuget feed that we get automatically with appveyor.

Unless you want to take a look now, I suggest we just keep only the dotnet pack part of appveyor.yml to keep that bit going, and then look to use github packages or similar for a CI feed in a follow-up

(also because I don't think I have permissions to remove the appveyor check so easiest to keep around in the meantime)

[mus65]

I was actually already looking into pushing to the GitHub NuGet Registry. I just finished it up and pushed it here.

NuGet result can be seen here: https://github.com/mus65/SSH.NET/pkgs/nuget/SSH.NET . This will not run for this PR because of the filter on the develop branch.

I will add a minimal appveyor.yml to avoid failure (just tested with an empty file, but that doesn't seem to work).

[mus65]

The NuGet package was pushed successfully on the develop branch, but it's not actually visible. I think this may be related to the Package permissions settings on the organization (which I obviously don't have access to).

[Rob-Hague]

Should be good now