[Bug]: EKS Workshop not working on AWS Free Accounts (new Free Tier)

### Installation method

Own AWS account

### What happened?

By default the Cloudformation template creates a EC2 instance of type t3.medium where the development environment runs. This type of instance is not supported in the new AWS Free Accounts. In us-west-2 and eu-west-1 these are the supported EC2 instance types:

```sh
aws ec2 describe-instance-types \
--filters Name=free-tier-eligible,Values=true \
--query "InstanceTypes[*].[InstanceType]" \
--output text | sort

c7i-flex.large
m7i-flex.large
t3.micro
t3.small
t4g.micro
t4g.small
```

The Cloudformation stack allways rolls back and the development environment can't be deployed.

### What did you expect to happen?

The EC2 instance type of the Cloudformation template should be selectable from a list of instances, so people using free accounts can use the Workshop too.

### How can we reproduce it?

Try to run the Cloudformation templates on a AWS Free Account.

### Anything else we need to know?

_No response_

### EKS version

N/A

Start by locating the CloudFormation templates that create the development environment and configure the t3.medium instance. Use the provided aws ec2 describe-instance-types command to verify eligible types in the target regions. Done means users can select a supported instance type and the CloudFormation stack deploys successfully on new AWS Free Accounts.

Written by the indexing model from the issue text.