Don't show server response in truss push errors

[helenlyang]

Summary

This PR removes the full server response from the Truss CLI console output on truss push errors. The console output will only include the message used to initialize the ApiError.

IIUC this is the only usage of ApiError; here, the ApiError message is set to the message of the first error in the server response.

Testing

I manually added a second remote to ~/.trussrc with an invalid API key:

[baseten]
remote_provider = baseten
api_key = {MY_ACTUAL_API_KEY}
remote_url = https://app.baseten.co
[baseten-invalid]
remote_provider = baseten
api_key = abc
remote_url = https://app.baseten.co

Running poetry run truss push and selecting the invalid remote with this change:

? 🎮 Which remote do you want to connect to? baseten-invalid
You have to log in to perform the request

Prior to this change:

? 🎮 Which remote do you want to connect to? baseten-invalid
You have to log in to perform the request
<Server response: {'errors': [{'message': 'You have to log in to perform the request', 'locations': [{'line': 3, 'column': 13}], 'path': ['models'], 'extensions': {'code': 'UNAUTHENTICATED_ACCESS'}}], 'data': {'models': None}}>

[linear]

BT-9122 Format truss errors better

In the Truss CLI, let's stop showing errors like this on push:

$ truss push
? 🎮 Which remote do you want to connect to? sid-staging
The user does not have the authorization to perform the request
<Server response: {'errors': [{'message': 'The user does not have the authorization to perform the request', 'locations': [{'line': 3, 'column': 13}], 'path': ['models'], 'extensions': {'code': 'UNAUTHORIZED_ACCESS'}}], 'data': {'models': None}}>

We should instead have a clearer error without the "Server response:" piece. Just remove that print for now

[squidarth]

I think you can remove all of this response stuff now and we can just pass for the whole class