bug#64829: Leaving .emacs.d/eln-cache on users disks not environmentally sound

[Dan Jacobson]

All I know is based on

https://emacs.stackexchange.com/questions/71825/how-often-should-emacs-28-1-native-compile-basic-emacs-files
and
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1041767
I am not even sure that these files piling up in
individual Debian users'
$HOME/.emacs.d/eln-cache/28.2-*
and never getting deleted
should be piling up there in the first place.

As far as "native-compile-prune-cache",
that is not something regular users know how to find or use.

Anyway, this is like some big oil spill.