AA brick configuration field error when using using username/password authentication

[twschiller]

Describe the bug

• https://pixiebrix.slack.com/archives/C042T2TBZ17/p1711407216348109
• AA CR username/password auth only supports one login at a time -- you can't be logged into both the CR and the API
• See screenshots in Slack

To Reproduce

Steps to reproduce the behavior:

1. Configure the Run Bot brick with username/password auth when you have an active session in Control Room

Discussion

• Need to discuss ways to gracefully handle, e.g., by invalidating the cached promises for the dropdowns. We also might need to have failed requests in the dropdown let the options component know the integration is bad. The UX of react-select is isn't very good for knowing how to resolve your issue
• If there's a failed request when using username/password-based configuration (or even if they're just using username/password-based configuration), it could be nice to show a message that the username/password based integration only works when they're not logged into Control Room web interface. Proposed copy: "The Control Room API cannot be called while you are logged into the Control Room web interface."