Fix label support for TotalNumberOfQueuedAndInProgressWorkflowRuns metric (#1390)

In #1373 we made two mistakes:

- We mistakenly checked if all the runner labels are included in the job labels and only after that it marked the target as eligible for scale. It should definitely be the opposite!
- We mistakenly checked for the existence of `self-hosted` labe l in the job. [Although it should be a good practice to explicitly say `runs-on: ["self-hosted", "custom-label"]`](https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#example-using-labels-for-runner-selection), that's not a requirement so we should code accordingly.

The consequence of those two mistakes was that, for example, jobs with `self-hosted` + `custom` labels didn't result in scaling runner with `self-hosted` + `custom` + `custom2`. This should fix that.

Ref #1056
Ref #1373

controllers/autoscaling.go

@@ -140,17 +140,23 @@ func (r *HorizontalRunnerAutoscalerReconciler) suggestReplicasByQueuedAndInProgr
 		} else {
 		JOB:
 			for _, job := range allJobs {
-				labels := make(map[string]struct{}, len(job.Labels))
-				for _, l := range job.Labels {
-					labels[l] = struct{}{}
+				runnerLabels := make(map[string]struct{}, len(st.labels))
+				for _, l := range st.labels {
+					runnerLabels[l] = struct{}{}
 				}
 
-				if _, ok := labels["self-hosted"]; !ok {
+				if len(job.Labels) == 0 {
+					// This shouldn't usually happen
+					r.Log.Info("Detected job with no labels, which is not supported by ARC. Skipping anyway.", "labels", job.Labels, "run_id", job.GetRunID(), "job_id", job.GetID())
 					continue JOB
 				}
 
-				for _, l := range st.labels {
-					if _, ok := labels[l]; !ok {
+				for _, l := range job.Labels {
+					if l == "self-hosted" {
+						continue
+					}
+
+					if _, ok := runnerLabels[l]; !ok {
 						continue JOB
 					}
 				}