Support Vultr Serverless Inference

[christhemorse]

Description

This PR adds support for the Vultr Serverless Inference product for the purpose of managing the subscription and viewing usage information.

Checklist:

• [x] Have you checked to ensure there aren't other open Pull Requests for the same update/change?
• [x] Have you linted your code locally prior to submission?
• [x] Have you successfully ran tests with your changes locally?

[github-actions[bot]]

Unit Tests and Coverage

Show Output

``` ? github.com/vultr/vultr-cli/v3 [no test files] ```

Pusher: @christhemorse, Action: pull_request_target

[github-actions[bot]]

Unit Tests and Coverage

Show Output

``` ? github.com/vultr/vultr-cli/v3 [no test files] ```

Pusher: @christhemorse, Action: pull_request_target

[github-actions[bot]]

Unit Tests and Coverage

Show Output

``` ? github.com/vultr/vultr-cli/v3 [no test files] ```

Pusher: @christhemorse, Action: pull_request_target

[github-actions[bot]]

Unit Tests and Coverage

Show Output

``` ? github.com/vultr/vultr-cli/v3 [no test files] ```

Pusher: @christhemorse, Action: pull_request_target