Improve a number of things about how MILC operates (#7344)

Improve a number of things about how MILC operates (#7344)

* Pull in updates for MILC

* Remove the shadow argparser
* Make it easier to reason about arguments and how they're translated into the config tree
* Populate self.config during init to support setting user.qmk_home for the global CLI
* Remove the short argument -c so that we can unambiguously determine the config file location without doing full argument processing
* Remove the --save-config option as it's a little confusing anyway
* Use Pathlib for path manipulation

* Fix commands with no arguments