There's a lot here. The main thing is that rather than invoking
`INNER_UNMAKE_PACKAGE`, we use the new `mach artifact install
--unfiltered-project-package` flag to do that work. In automation,
this gets configured using `MOZ_ARTIFACT_TASK` and is deterministic;
locally, this is far easier to work with.
This replacement allows us to clean up a bunch of Makefile goo, some
of which is done here. More clean up is surely possible; the
`mozharness` config files are a good place to look next.
The `MOZ_PKG_MAC_*` settings previously referred to the unpacked DMG
resources. There's no need for that complication; we can always take
them from the branding resources. (The relevant `mozconfig`
entries *look* to always have Nightly branding, but merge automation
ensures that the branding is correctly set for Beta and Release.)
Differential Revision: https://phabricator.services.mozilla.com/D249448
52347eb134