chore(examples): remove castai_rebalancing_schedules from most examples

`castai_rebalancing_schedule` is an organization-level resource while
most of our examples are in the scope of a single cluster. Trying to
create (and recreate) a rebalancing schedule from the same example (or
different examples) can lead to errors like:

```
│ Error: expected status code 200, received: status=409 body={"message":"Schedule with a name \"rebalance spots at every 30th minute\" already exists","fieldViolations":[]}
│
│   with castai_rebalancing_schedule.spots,
│   on castai.tf line 221, in resource "castai_rebalancing_schedule" "spots":
│  221: resource "castai_rebalancing_schedule" "spots" {
```

I'm removing `castai_rebalancing_schedules` and referencing `castai_rebalancing_job`s
in all examples but `gke/gke_clusters_with_workspaces` where
organization and cluster level are correctly separated. The data source
and resource examples also still remain in place.

Author: dvoros-castai

examples/aks/aks_cluster_existing/castai.tf

@@ -128,30 +128,3 @@ module "castai_aks_cluster" {
 
   install_omni = true
 }
-
-resource "castai_rebalancing_schedule" "default" {
-  name = "rebalance nodes at every 30th minute"
-  schedule {
-    cron = "CRON_TZ=America/Argentina/Buenos_Aires */30 * * * *"
-  }
-  trigger_conditions {
-    savings_percentage = 20
-  }
-  launch_configuration {
-    # only consider instances older than 5 minutes
-    node_ttl_seconds         = 300
-    num_targeted_nodes       = 3
-    rebalancing_min_nodes    = 2
-    keep_drain_timeout_nodes = false
-    execution_conditions {
-      enabled                     = true
-      achieved_savings_percentage = 10
-    }
-  }
-}
-
-resource "castai_rebalancing_job" "default" {
-  cluster_id              = module.castai_aks_cluster.cluster_id
-  rebalancing_schedule_id = castai_rebalancing_schedule.default.id
-  enabled                 = true
-}

examples/eks/eks_cluster_autoscaler_policies/castai.tf

@@ -217,41 +217,3 @@ module "castai-eks-cluster" {
   # module "castai-eks-cluster" has to be destroyed before module "castai-eks-role-iam".
   depends_on = [module.castai-eks-role-iam, module.vpc, module.eks]
 }
-
-resource "castai_rebalancing_schedule" "spots" {
-  name = "rebalance spots at every 30th minute"
-  schedule {
-    cron = "*/30 * * * *"
-  }
-  trigger_conditions {
-    savings_percentage = 20
-  }
-  launch_configuration {
-    # only consider instances older than 5 minutes
-    node_ttl_seconds         = 300
-    num_targeted_nodes       = 3
-    rebalancing_min_nodes    = 2
-    keep_drain_timeout_nodes = false
-    selector = jsonencode({
-      nodeSelectorTerms = [{
-        matchExpressions = [
-          {
-            key      = "scheduling.cast.ai/spot"
-            operator = "Exists"
-          }
-        ]
-      }]
-    })
-    execution_conditions {
-      enabled                     = true
-      achieved_savings_percentage = 10
-    }
-  }
-}
-
-resource "castai_rebalancing_job" "spots" {
-  cluster_id              = castai_eks_clusterid.cluster_id.id
-  rebalancing_schedule_id = castai_rebalancing_schedule.spots.id
-  enabled                 = true
-  depends_on              = [module.castai-eks-cluster]
-}

examples/eks/eks_cluster_existing/castai.tf

@@ -194,41 +194,3 @@ module "castai_eks_cluster" {
   # module "castai-eks-cluster" has to be destroyed before module "castai-eks-role-iam".
   depends_on = [module.castai_eks_role_iam]
 }
-
-resource "castai_rebalancing_schedule" "spots" {
-  name = "rebalance spots at every 30th minute"
-  schedule {
-    cron = "*/30 * * * *"
-  }
-  trigger_conditions {
-    savings_percentage = 20
-  }
-  launch_configuration {
-    # only consider instances older than 5 minutes
-    node_ttl_seconds         = 300
-    num_targeted_nodes       = 3
-    rebalancing_min_nodes    = 2
-    keep_drain_timeout_nodes = false
-    selector = jsonencode({
-      nodeSelectorTerms = [{
-        matchExpressions = [
-          {
-            key      = "scheduling.cast.ai/spot"
-            operator = "Exists"
-          }
-        ]
-      }]
-    })
-    execution_conditions {
-      enabled                     = true
-      achieved_savings_percentage = 10
-    }
-  }
-}
-
-resource "castai_rebalancing_job" "spots" {
-  cluster_id              = castai_eks_clusterid.cluster_id.id
-  rebalancing_schedule_id = castai_rebalancing_schedule.spots.id
-  enabled                 = true
-  depends_on              = [module.castai_eks_cluster]
-}