Add GitHub Actions SetOutput Command

[gitfool]

Feature request: create or update an output for any steps running next in a job to avoid the following warning with latest runner:

The `set-output` command is deprecated and will be disabled soon. Please upgrade to using Environment Files.

References:

• GitHub Actions: Deprecating save-state and set-output commands
• Workflow commands for GitHub Actions: Setting an output parameter

[devlead]

Are we talking about the Cake Common GitHubActions Build provider? It currently uses an environment file for the SetEnvironmentVariable command

cake/src/Cake.Common/Build/GitHubActions/Commands/GitHubActionsCommands.cs

Lines 80 to 104 in 50dc560

	public void SetEnvironmentVariable(string key, string value)
	{
	if (string.IsNullOrEmpty(key))
	{
	throw new ArgumentNullException(nameof(key));
	}
	if (value is null)
	{
	throw new ArgumentNullException(nameof(value));
	}
	if (_actionsEnvironment.Runtime.EnvPath == null)
	{
	throw new CakeException("GitHub Actions Runtime EnvPath missing.");
	}
	var file = _fileSystem.GetFile(_actionsEnvironment.Runtime.EnvPath);
	using var stream = file.Open(FileMode.Append, FileAccess.Write, FileShare.None);
	using var writer = new StreamWriter(stream);
	writer.Write(key);
	writer.WriteLine("<<CAKEEOF");
	writer.WriteLine(value);
	writer.WriteLine("CAKEEOF");
	}

And similar should be done for Setting an output parameter using GITHUB_OUTPUT variable?

[gitfool]

Exactly.

[devlead]

Sounds like a reasonable addition to me, something you would like to send a PR for? If so please raise an issue and I'll assign it to you.