Jocelyn Vernay

[GSK-2782] Allow GiskardClient to read api key from env

1

## Description There exists an env var called `GSK_API_KEY` used to [auto-provide the API key](https://github.com/Giskard-AI/giskard/blob/6f9bc5f9008f9688a5f894ad498d4f1ec45bf265/giskard/commands/cli_worker.py#L71) in the giskard worker CLI. It makes sense to reuse the name here. We may...