enhance(actions): show the steps the runner reports (#39720)

Gitea derives the steps of a job from the workflow file, so the `pre`
and `post` steps of actions only show up inside "Set up job" and
"Complete job".
Fixes https://github.com/go-gitea/gitea/issues/24604.

A runner can now report the steps it actually runs, and Gitea shows
those instead. Runners that don't report them keep the current view, and
older Gitea versions ignore them.

Related:
- Proto: https://gitea.com/gitea/actions-proto-def/pulls/19
- Runner: https://gitea.com/gitea/runner/pulls/1293

routers/api/actions/job_summary.go

@@ -41,7 +41,7 @@ func uploadJobSummary(ctx *ArtifactContext) {
 		ctx.HTTPError(http.StatusInternalServerError, "Error getting task steps")
 		return
 	}
-	if !slices.ContainsFunc(steps, func(s *actions_model.ActionTaskStep) bool { return s.Index == stepIndex }) {
+	if !slices.ContainsFunc(steps, func(s *actions_model.ActionTaskStep) bool { return s.WorkflowStepIndex() == stepIndex }) {
 		ctx.HTTPError(http.StatusBadRequest, "step_index mismatch")
 		return
 	}