Update 38-rpi-pibrella.js

[cymplecy]

Update to work with python3 on Bullseye

• [ x] Bugfix (non-breaking change which fixes an issue)

Proposed changes

Updates node to work using Python3 in Bullseye

Checklist

• [x] I have read the contribution guidelines

[linux-foundation-easycla[bot]]

The committers listed above are authorized under a signed CLA.

• :white_check_mark: login: cymplecy / name: Simon Walters (67fc0902560891154d261b7df806a525062da7e4)

[cymplecy]

Forum link

https://discourse.nodered.org/t/node-red-node-pibrella-missing-rpi-gpio-python-library/80654

[dceejay]

Thanks for the update