Remove dependencies on the now defunction apt.matrix.one apt mirror

[benfrancis]

Heads up: The toolchain images used to build this add-on used to pull down the libmatrixio-creator-hal-dev .deb package from the https://apt.matrix.one/raspbian apt mirror.

It appears that apt mirror no longer exists since the company went bust.

I'm going to have to remove this package from the toolchain, so some work may be needed in order to release a new version of this add-on using the release workflow in this repo, if the build fails without that dependency.