Add worker support to mobile install V3 actions

[Bencodes]

Mobile install V3 lacks worker support for some of it's more expensive actions.

The main one that stands out in my initial testing is the DesugarDexSharding.

[ted-xie]

I initially thought this issue could be localized to just fixing the worker compatibility for core library desugaring, which was indeed a blocker, but it actually goes deeper than that: src/tools/ak/dex itself needs to be made worker-compatible, which will take a bit more effort. I don't want to gate the 0.6.1 release on this, so I'll move this issue to the 0.7.0 tracker, and possibly a 0.6.2 if we deem that necessary.