enhance: report a GitHub-style "Set up job" section (#1089)

Reshapes the job log's "Set up job" section to mirror `actions/runner`:

- runner name/version, then `Runner Information` (labels, task, job, repository, event) and `Operating System` groups
- every required action downloaded up front under `Prepare all required actions`, each as `Download action repository '<action>@<ref>' (SHA:<sha>)`
- `Complete job name` closes the section

Downloading up front is the one behavioral change: the same set was already fetched during the pre stage regardless of a step's `if`, now just before the first pre step, so a download failure is reported against the job rather than a step.

---------

Co-authored-by: silverwind <me@silverwind.io>
Reviewed-on: https://gitea.com/gitea/runner/pulls/1089
Reviewed-by: silverwind <2021+silverwind@noreply.gitea.com>

act/runner/step.go

@@ -107,7 +107,13 @@ func runStepExecutor(step step, stage stepStage, executor common.Executor) commo
 		if strings.Contains(stepString, "::add-mask::") {
 			stepString = "add-mask command"
 		}
-		logger.Infof("Run %s %s", stage, stepString)
+		if stage == stepStageMain {
+			// Main steps print their own raw "Run <title>" header, so this line is redundant and
+			// only leaks into the "Set up job" section for the first step; keep it as a debug trace.
+			logger.Debugf("Run %s %s", stage, stepString)
+		} else {
+			logger.Infof("Run %s %s", stage, stepString)
+		}
 
 		// Prepare and clean Runner File Commands
 		actPath := rc.JobContainer.GetActPath()