Expected behaviour
The run button should not stay greyed out.

Actual behaviour
At the moment, the run button is greyed out for a short period of time while pyodide loads. However, if the user pastes some code into the editor that requires the use of skulpt before pyodide has fully loaded, the run button stays greyed out. This is likely due to an ongoing mismatch between the active runner and the loaded runner in the redux store. See video below for a short demo of the bug ⤵

Steps to reproduce
See video above.

Additional context
Related to 137: https://github.com/RaspberryPiFoundation/digital-editor-issues/issues/137

I don't know if this ticket is related but there's a similar issue here: https://github.com/RaspberryPiFoundation/digital-editor-issues/issues/533