instead of building the packaged binaries with the `bindata` tag, this
introduces a new forgejo-common package which contains common assets and
architecture independent files.
This is the first of a handful of PRs that will ultimately enable
building packages for multiple architectures.
in addition to using the checkout action for all the fetches, this will
make sure we get a deep clone of the repository that can be used to
resolve tags for pull requests if the submodule is ahead of the latest
tag in the main origin
this should be the last complex revert PR
setting up a user friendly migration path for the repo component switch
ended up being a lot more complicated than I initially expected
there will be one more cleanup PR after this