[Feature] add chart for net-gateway-api

[Ahhhh-man]

Name and Version

n/a

What is the problem this feature will solve?

Another knative chart that should be migrated to helm.

https://github.com/knative-extensions/net-gateway-api

What is the feature you are proposing to solve the problem?

New chart called net-gateway-api

What alternatives have you considered?

No response

Code of Conduct

• I agree to follow this project's Code of Conduct