fix(ecs): Allow scheduling DAEMON services even if no EC2 capacity at…

…tached to cluster (#25306)

It can be useful to allow DAEMON services to be scheduled to a cluster
even if there is no EC2 capacity attached to it yet, under the
assumption that capacity will be attached to the cluster later. We no
longer fail validation if this happens.

packages/aws-cdk-lib/aws-ecs/lib/ec2/ec2-service.ts

@@ -249,7 +249,7 @@ export class Ec2Service extends BaseService implements IEc2Service {
    */
   private validateEc2Service(): string[] {
     const ret = new Array<string>();
-    if (!this.cluster.hasEc2Capacity) {
+    if (!this.daemon && !this.cluster.hasEc2Capacity) {
       ret.push('Cluster for this service needs Ec2 capacity. Call addXxxCapacity() on the cluster.');
     }
     return ret;