Improve Arduino library CI

[peternewman]

Rework of #35 .

Given:

Please add top the existing github actions

Originally posted by @mathertel in https://github.com/mathertel/DmxSerial2/issues/35#issuecomment-1018703462

Are you happy for me to do this?: I would suggest switching to a matrix makes the config simpler to read and tweak.

Originally posted by @peternewman in https://github.com/mathertel/DmxSerial2/issues/35#issuecomment-875186269