Improve the support for reusable workflows (#122)

Fix [#32439](https://github.com/go-gitea/gitea/issues/32439)

- Support reusable workflows with conditional jobs
- Support nesting reusable workflows

Reviewed-on: https://gitea.com/gitea/act/pulls/122
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>
Reviewed-by: Jason Song <wolfogre@noreply.gitea.com>
Co-authored-by: Zettat123 <zettat123@gmail.com>
Co-committed-by: Zettat123 <zettat123@gmail.com>

pkg/runner/runner.go

@@ -210,6 +210,9 @@ func (runner *runnerImpl) NewPlanExecutor(plan *model.Plan) common.Executor {
 					if len(rc.String()) > maxJobNameLen {
 						maxJobNameLen = len(rc.String())
 					}
+					if rc.caller != nil { // For Gitea
+						rc.caller.setReusedWorkflowJobResult(rc.JobName, "pending")
+					}
 					stageExecutor = append(stageExecutor, func(ctx context.Context) error {
 						jobName := fmt.Sprintf("%-*s", maxJobNameLen, rc.String())
 						executor, err := rc.Executor()
@@ -281,3 +284,10 @@ func (runner *runnerImpl) newRunContext(ctx context.Context, run *model.Run, mat
 
 	return rc
 }
+
+// For Gitea
+func (c *caller) setReusedWorkflowJobResult(jobName string, result string) {
+	c.updateResultLock.Lock()
+	defer c.updateResultLock.Unlock()
+	c.reusedWorkflowJobResults[jobName] = result
+}