Add GitHub Actions SetStepSummary Command

Prerequisites

[X] I have written a descriptive issue title
[X] I have searched issues to ensure it has not already been reported

Cake runner

Cake .NET Tool

Cake version

2.3.0

Operating system

Linux

Operating system architecture

64-Bit

CI Server

GitHub Actions

What are you seeing?

Following up from #4009, it makes sense to create a SetStepSummary method, which works in a very similar way.

https://docs.github.com/en/actions/using-workflows/workflow-commands-for-github-actions#adding-a-job-summary

What is expected?

It should be possible to write markdown content to the GitHub Step Summary environment variable location, and the summary should appear in the summary for the workflow.

Steps to Reproduce

N/A.

Output log

N/A

cake-build / cake

Add GitHub Actions SetStepSummary Command #4011