Bug#1056939: auctex: auctex is incompatible with use-package/elpa

[Xiyue Deng]

I have made a new MR[1] using a separate branch so that I can continue
to experiment on master.  It also changes how *-pkg.el is generated.
PTAL.

-- 
Xiyue Deng

[1] https://salsa.debian.org/salve/auctex/-/merge_requests/4