[platform] Fix stale workloads not being deleted (#1210)

Workloads tracking an object undergoing deletion can be reconciled when
the object is marked for deletion, but is not yet removed. After the
object is deleted, there is no event to trigger another reconciliation
of the workload and it might never get deleted until a global reconcile
happens or the controller is restarted. This patch ensures they are
requeued in the reconciliation loop.

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## What this PR does


### Release note

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```release-note
[platform] Fix stale workloads not being deleted
```

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-->

## Summary by CodeRabbit

* **Improvements**
* Added a delay before reprocessing items that are being deleted,
resulting in more efficient handling of deletions.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

internal/controller/workload_controller.go

@@ -3,6 +3,7 @@ package controller
 import (
 	"context"
 	"strings"
+	"time"
 
 	corev1 "k8s.io/api/core/v1"
 	apierrors "k8s.io/apimachinery/pkg/api/errors"
@@ -15,6 +16,10 @@ import (
 	cozyv1alpha1 "github.com/cozystack/cozystack/api/v1alpha1"
 )
 
+const (
+	deletionRequeueDelay = 30 * time.Second
+)
+
 // WorkloadMonitorReconciler reconciles a WorkloadMonitor object
 type WorkloadReconciler struct {
 	client.Client
@@ -52,6 +57,9 @@ func (r *WorkloadReconciler) Reconcile(ctx context.Context, req ctrl.Request) (c
 
 	// found object, nothing to do
 	if err == nil {
+		if !t.GetDeletionTimestamp().IsZero() {
+			return ctrl.Result{RequeueAfter: deletionRequeueDelay}, nil
+		}
 		return ctrl.Result{}, nil
 	}