[io] Croud related IO subsystem tests may fail when a croud configuration file exist for the local user

Some croud related IO subsystem tests may fail when a local croud configuration settings for the local user exists. These settings will be taken into account and passed to the croud API, causing the mocked croud calls to not match anymore.

Failing tests:
- `cratedb_toolkit.io.croud.test_import_url`
- `cratedb_toolkit.io.croud.test_import_file`

They are failing in my setup when the stored croud.yml configuration file contains a different endpoint, example:
```
current-profile: dev
profiles:
dev:
endpoint: https://console.cratedb-dev.cloud
```