[Dev] do we need the [kernels], [cross], and [unmaintained] repos anymore?

[bill-auger]

i was just updating pbot's factoid about the available kernels -
im not sure why any of these repo was ever needed really; but
now there are only two packages in [i686/kernels] - both have
not been updated since january - there is nothing for the other
arches; and [cross] is empty for all arches

* i686/kernels/linux-libre-aarch64 5.4.8
* i686/kernels/linux-libre-x86_64 5.4.8

i also noticed 'linux-libre-64' in [i686/libre] - that is more
recent than the other new (undocumented) ones - is there any
difference between 'linux-libre-64' and 'linux-libre-x86_64'? -
and why are these only in the i686 repos?

* i686/libre/linux-libre-64 5.6.12

what is the use case for those foreign kernels? - are they
experimental, or something we should document? - maybe its a
good time to nail down the semantics of what goes in [kernels]
and [cross]; or maybe decide if those specialty repos are any
longer needed

the wiki is not very helpful for understanding their original
intentions

  [libre]
  "contains non-standard kernels such as "long term support with
  stealth TCP sockets patches" kernels oriented towards servers,
  or kernels compiled with AppArmor, TOMOYO, SMACK and SELinux
  support"

  [cross]
  "contains mostly-unsupported packages that contain tool-chains
  for cross-compiling for a different architecture"

IMHO we do not want any permanently "unsupported packages" - we
have the personal name-spaces for experimentation; and there is
another repo which is named: [unmaintained] - though again i
think there should not be any unsupported nor unmaintained
packages in the system - a "PUR" PKGBUILD repos would serve that
purpose better

we have discussed adding a something like a [build-tools] repo,
for to hide 'pip' and other sharp kitchen utensils - maybe we
could rename and re-purpose [cross] for that?