This packages the megapixels fork that purism has supporting the librem
5.
The `provides="megapixels"` is there so that apk doesn't try to install
both megapixels and this package side-by-side. If the user explicitly
installs megapixels-purism, apk will remove megapixels first. The
original megapixels is still preferred by apk by default.
[ci:skip-build]: already built successfully in CI
