Update `microphone.sound_level()` to use new CODAL features

[microbit-carlos]

A continuation from the discussion in:

• https://github.com/microbit-foundation/micropython-microbit-v2/issues/114

The CODAL updates have been pushed, but a new tag is not released yet (that'll take a few days more as other bug fixes are implemented):

• https://github.com/lancaster-university/codal-microbit-v2/issues/225#issuecomment-1241023894

[microbit-carlos]

@dpgeorge CODAL v0.2.42 has been released:

• https://github.com/lancaster-university/codal-microbit-v2/releases/tag/v0.2.42
• https://github.com/lancaster-university/codal-microbit-v2/compare/v0.2.41...v0.2.42

[dpgeorge]

New CODAL interface is used by c5ab62716a72147893f8e3672f3f5fb177925e1f

[microbit-carlos]

As a heads up, I've raised this issue in the CODAL repo about this version of the audio.level:

• https://github.com/lancaster-university/codal-microbit-v2/issues/236