[ECS] [Networking]: Support T4g Instances in ENI Trunking

### Community Note

* Please vote on this issue by adding a 👍 [reaction](https://blog.github.com/2016-03-10-add-reactions-to-pull-requests-issues-and-comments/) to the original issue to help the community and maintainers prioritize this request
* Please do not leave "+1" or "me too" comments, they generate extra noise for issue followers and do not help prioritize the request
* If you are interested in working on this issue or have submitted a pull request, please leave a comment

**Tell us about your request**

Support the new [T4g](https://aws.amazon.com/ec2/instance-types/t4/) Instances in [ENI Trunking](https://docs.aws.amazon.com/AmazonECS/latest/developerguide/container-instance-eni.html).

**Which service(s) is this request for?**
ECS.

**Tell us about the problem you're trying to solve. What are you trying to do, and why is it hard?**
Currently I have thousand of ECS Services' running on `bridge` network mode and I'm planning to move to 'awsvpc' network mode, however, my current environment is greatly cost optimised. Doing this kind of movement right now implies in a significant cost increase, that could be minimised if T4g comes to be supported for ENI Trunking.

**Are you currently working around this issue?**
No.

The request concerns AWS ECS ENI Trunking support for T4g instances. Start by reviewing the linked T4g and ENI Trunking documentation and the existing ECS support context; done means T4g instances are officially supported for ENI Trunking.

Written by the indexing model from the issue text.