Bug on upgrade to v1.6.1

### Describe the Bug

Hi there 👋 ,
After upgrading the module to v1.6.1, our logs stopped getting forwarged to Datadog.
I found the following error on CloudWatch:

> [ERROR] Runtime.ImportModuleError: Unable to import module 'lambda_function': cannot import name 'formatargspec' from 'inspect' (/var/lang/lib/python3.11/inspect.py)

After downgrading, it worked again.

### Expected Behavior

Logs getting forwarded to Datadog properly

### Steps to Reproduce

Use the module like this:
```

module "datadog-lambda-forwarder" {
source = "cloudposse/datadog-lambda-forwarder/aws"
version = "1.6.1"
forwarder_log_enabled = true

dd_tags_map = {
Environment = "production"
}

name = "datadog_log_forwarder_production"
lambda_memory_size = 1024
lambda_timeout = 900
dd_api_key_source = {
resource = "ssm"
identifier = "[redacted]"
}

```

### Screenshots

_No response_

### Environment

- Terraform 1.8.0

### Additional Context

_No response_