[Bug] Code appears to run without any tab open

[laurensvalk]

Describe the bug
When connected but no code tab is open, the play button is clickable. There appears to be a download progress animation but nothing happens.

To reproduce
Steps to reproduce the behavior:

1. Have used Pybricks in the past.
2. For bonus point, let settings be the last tab you used.
3. Open Pybricks Beta.
4. Connect to a hub.
5. Press play.

Expected behavior
Button not clickable, and no download progress.

Screenshots