Failed to set env var when using kubetest2

[prateekgogia]

/kind bug

1. What kops version are you running? The command kops version, will display
this information.
Client version: 1.26.3 (git-v1.26.3)

2. What Kubernetes version are you running? kubectl version will print the
version if a cluster is running or provide the Kubernetes version specified as
a kops flag.
1.27

3. What cloud provider are you using?
aws

4. What commands did you run? What is the simplest way to reproduce this issue?

kubetest2 kops -v=2 --cloud-provider=aws --cluster-name=scalability1.k8s.local --kops-binary-path=/Users/pgogia/workspace/golang/src/k8s.io/bin/kops --admin-access=0.0.0.0/0 --env=KOPS_FEATURE_FLAGS=ClusterAddons, --validation-wait=30m --up --kubernetes-version=v1.27.4 '--create-args=--networking=amazonvpc --set cluster.spec.networking.amazonVPC.env=ENABLE_PREFIX_DELEGATION=true --image=ssm:/aws/service/canonical/ubuntu/server/20.04/stable/current/arm64/hvm/ebs-gp2/ami-id --set spec.kubeScheduler.authorizationAlwaysAllowPaths=/healthz --set spec.kubeScheduler.authorizationAlwaysAllowPaths=/metrics --node-count=500 --node-size=c6g.medium --control-plane-count=3 --master-size=c6g.16xlarge'

5. What happened after the commands executed?
Fails with this error

Error: cannot set field "spec.networking.amazonVPC.env": unhandled type "kops.EnvVar"
Error: exit status 1

6. What did you expect to happen?
Cluster creation to succeed

7. Please provide your cluster manifest. Execute
kops get --name my.example.com -o yaml to display your cluster manifest.
You may want to remove your cluster name and other sensitive information.

8. Please run the commands with most verbose logging by adding the -v 10 flag.
Paste the logs into this report, or in a gist and provide the gist link here.

9. Anything else do we need to know?
I am trying to set the env var for amazon vpc cni like this --set cluster.spec.networking.amazonVPC.env=ENABLE_PREFIX_DELEGATION=true but seems like the type "kops.EnvVar" is not handled here in setType function.