[BUG][kotlin][client] doesn't annotate api call exceptions

[4brunu]

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• What's the version of OpenAPI Generator used?
• Have you search for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Bounty to sponsor the fix (example)

Description

When making a request to a server, there is a possibility of throwing an error, but that's not annotated.

openapi-generator version

4.20.0

Suggest a fix

Annotated the api calls with the respective exceptions.

[auto-labeler]

👍 Thanks for opening this issue!
🏷 I have applied any labels matching special text in your issue.

The team will review the labels and make any necessary changes.