x11-themes/papirus-icon-theme: Update to 20191201

Delete pkg-plist and dynamically generate the plist instead to ease
future updates. pkg-plist was 4.1 MiB large and had over 70000
entries. This also bloated the patch accordingly to the point it
had to be gzipped to not go over Bugzilla's size limit for attachments.
It was still over 100 KiB compressed.

Changes: https://github.com/PapirusDevelopmentTeam/papirus-icon-theme/releases
PR: 242351
Submitted by: Hiroki Tagato <tagattie@yandex.com> (maintainer)