Prevent optimistic lock errors during 'MaintainShootAnnotations' step

Signed-off-by: ialidzhikov <i.alidjikov@gmail.com>

```improvement user
An issue causing Shoot reconciliation to fail at `Maintain shoot annotations` with optimistic lock error message is now mitigated.
```

pkg/gardenlet/controller/shoot/shoot_control_reconcile.go

@@ -394,11 +394,6 @@ func (c *Controller) runReconcileShootFlow(o *operation.Operation) *gardencorev1
 			Fn:           flow.TaskFn(botanist.WaitUntilExtensionResourcesDeleted).SkipIf(o.Shoot.HibernationEnabled),
 			Dependencies: flow.NewTaskIDs(deleteStaleExtensionResources),
 		})
-		_ = g.Add(flow.Task{
-			Name:         "Maintain shoot annotations",
-			Fn:           flow.TaskFn(botanist.MaintainShootAnnotations),
-			Dependencies: flow.NewTaskIDs(deleteStaleExtensionResources),
-		})
 		deployContainerRuntimeResources = g.Add(flow.Task{
 			Name:         "Deploying container runtime resources",
 			Fn:           flow.TaskFn(botanist.DeployContainerRuntimeResources).RetryUntilTimeout(defaultInterval, defaultTimeout),
@@ -424,11 +419,16 @@ func (c *Controller) runReconcileShootFlow(o *operation.Operation) *gardencorev1
 			Fn:           flow.TaskFn(botanist.RestartControlPlanePods).DoIf(requestControlPlanePodsRestart),
 			Dependencies: flow.NewTaskIDs(deployKubeControllerManager, deployControlPlane, deployControlPlaneExposure),
 		})
-		_ = g.Add(flow.Task{
+		deployVPA = g.Add(flow.Task{
 			Name:         "Deploying Kubernetes vertical pod autoscaler",
 			Fn:           flow.TaskFn(botanist.DeployVerticalPodAutoscaler).RetryUntilTimeout(defaultInterval, defaultTimeout),
 			Dependencies: flow.NewTaskIDs(deploySecrets, waitUntilKubeAPIServerIsReady, deployManagedResources, hibernateControlPlane),
 		})
+		_ = g.Add(flow.Task{
+			Name:         "Maintain shoot annotations",
+			Fn:           flow.TaskFn(botanist.MaintainShootAnnotations),
+			Dependencies: flow.NewTaskIDs(deployVPA),
+		})
 	)
 
 	for k, v := range botanist.Shoot.Components.Extensions.DNS.AdditionalProviders {