Inactive maintainer package orphaning

[Jon Turney]

I've orphaned the following packages:

chere                                        Dave Kilroy
ELFIO                                        Serge Lamikhov-Center
task                                         Federico Hernandez
tftp                                         Gernot Hillier

The maintainers of which have been inactive for a long time, and didn't 
respond to my attempts to contact them.

Consequently, these maintainers' (long unused) ssh keys are also disabled.


These packages are all leaves in the dependency tree, and so maybe also 
candidates for removal:

chere ('Cygwin Prompt Here') is probably still used and useful, but 
could probably benefit from some love and better integration (as 
discussed at [1], nearly a year ago now, sigh...)

[1] https://cygwin.com/pipermail/cygwin/2024-February/255441.html

tftpd is potentially useful for booting really dumb pieces of hardware, 
but the version we provide is so old, this may be a disservice.

ELFIO (which should perhaps be named elfio-devel) is a header-only 
library, so may be build-time dependency of other packages. 
Unfortunately that information is not recorded for many older packages.
My brief searches haven't discovered any users of it.