Incorrect AWS provider version requirement

### Describe the Bug

The AWS provider requirement is still listed as >=2.x, but creating an instance with this module with an AWS provider version <5.x will result in the error `Can't configure a value for "domain": its value will be decided automatically based on the result of applying this configuration.` due to attempting to set the "domain" value on main.tf:181

### Expected Behavior

No errors about setting derived attributes that can't be set or overridden in any way without back-versioning the module to a version where this line doesn't exist

### Steps to Reproduce

Attempt to create an instance using this module, with AWS provider <5.x

### Screenshots

```
╷
│ Error: Value for unconfigurable attribute
│
│ with module.ec2_zscaler.aws_eip.additional,
│ on .terraform/modules/ec2_zscaler/eni.tf line 29, in resource "aws_eip" "additional":
│ 29: domain = "vpc"
│
│ Can't configure a value for "domain": its value will be decided
│ automatically based on the result of applying this configuration.
╵
╷
│ Error: Value for unconfigurable attribute
│
│ with module.ec2_zscaler.aws_eip.default,
│ on .terraform/modules/ec2_zscaler/main.tf line 181, in resource "aws_eip" "default":
│ 181: domain = "vpc"
│
│ Can't configure a value for "domain": its value will be decided
│ automatically based on the result of applying this configuration.
╵
```

### Environment

_No response_

### Additional Context

_No response_