chore(elbv2-targets): fix broken integration tests (#19696)

I'll create a follow up issue for this. We should be adding this
dependency automatically. Without this we get the error message
"If the target type is ALB, the target must have at least one listener that matches the target group port or any specified port overrides"
because the NLB target group is being created before the ALB listener


----

### All Submissions:

* [ ] Have you followed the guidelines in our [Contributing guide?](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md)

### Adding new Unconventional Dependencies:

* [ ] This PR adds new unconventional dependencies following the process described [here](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md/#adding-new-unconventional-dependencies)

### New Features

* [ ] Have you added the new feature to an [integration test](https://github.com/aws/aws-cdk/blob/master/INTEGRATION_TESTS.md)?
	* [ ] Did you use `cdk-integ` to deploy the infrastructure and generate the snapshot (i.e. `cdk-integ` without `--dry-run`)?

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

packages/@aws-cdk/aws-elasticloadbalancingv2-targets/test/integ.alb-target.expected.json

@@ -18,11 +18,11 @@
     "VpcPublicSubnet1Subnet5C2D37C4": {
       "Type": "AWS::EC2::Subnet",
       "Properties": {
-        "CidrBlock": "10.0.0.0/18",
         "VpcId": {
           "Ref": "Vpc8378EB38"
         },
         "AvailabilityZone": "test-region-1a",
+        "CidrBlock": "10.0.0.0/18",
         "MapPublicIpOnLaunch": true,
         "Tags": [
           {
@@ -115,11 +115,11 @@
     "VpcPublicSubnet2Subnet691E08A3": {
       "Type": "AWS::EC2::Subnet",
       "Properties": {
-        "CidrBlock": "10.0.64.0/18",
         "VpcId": {
           "Ref": "Vpc8378EB38"
         },
         "AvailabilityZone": "test-region-1b",
+        "CidrBlock": "10.0.64.0/18",
         "MapPublicIpOnLaunch": true,
         "Tags": [
           {
@@ -180,11 +180,11 @@
     "VpcPrivateSubnet1Subnet536B997A": {
       "Type": "AWS::EC2::Subnet",
       "Properties": {
-        "CidrBlock": "10.0.128.0/18",
         "VpcId": {
           "Ref": "Vpc8378EB38"
         },
         "AvailabilityZone": "test-region-1a",
+        "CidrBlock": "10.0.128.0/18",
         "MapPublicIpOnLaunch": false,
         "Tags": [
           {
@@ -242,11 +242,11 @@
     "VpcPrivateSubnet2Subnet3788AAA1": {
       "Type": "AWS::EC2::Subnet",
       "Properties": {
-        "CidrBlock": "10.0.192.0/18",
         "VpcId": {
           "Ref": "Vpc8378EB38"
         },
         "AvailabilityZone": "test-region-1b",
+        "CidrBlock": "10.0.192.0/18",
         "MapPublicIpOnLaunch": false,
         "Tags": [
           {
@@ -631,7 +631,11 @@
         "VpcId": {
           "Ref": "Vpc8378EB38"
         }
-      }
+      },
+      "DependsOn": [
+        "ServiceLBPublicListenerECSGroup0CC8688C",
+        "ServiceLBPublicListener46709EAA"
+      ]
     }
   },
   "Outputs": {

packages/@aws-cdk/aws-elasticloadbalancingv2-targets/test/integ.alb-target.ts

@@ -32,13 +32,14 @@ class TestStack extends Stack {
       port: 80,
     });
 
-    listener.addTargets('Targets', {
+    const target = listener.addTargets('Targets', {
       targets: [new targets.AlbTarget(svc.loadBalancer, 80)],
       port: 80,
       healthCheck: {
         protocol: elbv2.Protocol.HTTP,
       },
     });
+    target.node.addDependency(svc.listener);
 
     new CfnOutput(this, 'NlbEndpoint', { value: `http://${nlb.loadBalancerDnsName}` });
   }