let's drop libparse-keyword-perl and its reverse dependencies

[intrigeri]

Hi Jonas, Florian, team!

Jonas Smedegaard (2021-02-24):
> I would appreciate if someone would take a second look to ensure I 
> didn't miss something

I checked and your analysis & conclusion look entirely sound to me.
"dak rm -Rn" confirms this set of removal would work.

> and preferably if they agree they file this as a 
> removal request for ftpmaster (so that I can move on to other tasks).

I'll do that.

Cheers!