Noto fonts are available with sources and fully libre CI build systems at
GitHub.com/notofonts and follow open source development methodology,
although they use the format preferred by the font designer. Some use sfd,
one even uses their own custom font code in python, but - as in the
majority of the font development industry - the majority use glyphsapp.
Google Fonts has invested significant resources into making the noto fonts
as libre as practical given industry norms and preferences: Anyone CAN
provide a patch to the source files via GitHub PR, and Google maintains the
libre glyphsLib python package to convert .ufo to .glyphs, and almost every
editor today supports UFO.
Google Fonts also sponsored development of the fontforge ufo import export
support, as well as numerous modern libre font editors projects (trufont,
mfek, fontra) that are all UFO based.
I would be happy to directly connect anyone with the current noto
maintainer, Simon Cozens, if they would like to discuss contribution, but
all GitHub issues on all repos in the org go to him, so I encourage you to
just post an issue :)
Simon will be especially interested in specific details about what makes
packaging the Google fontmake/gfbuilder build systems difficult for Fedora
to package :)