Remove publickey(5) stuff

[manu]

Summary

This uses DES and it's likely that nobody uses that in 2021.
If somebody uses this we help them by deprecating and removing this.

[emaste]

Are chkey / newkey part of this too?

[manu]

In D30683#689315, @emaste wrote:

Are chkey / newkey part of this too?

Looks like they are, will update later.

[manu]

Include chkey/newkey

[lwhsu]

ObsoleteFiles.inc

49

Should we also remove other man pages like usr/share/man/man1/chkey.1.gz ?

[manu]

Remove man pages too

[emaste]

Deprecation notice was added in d5ef73a71f0e2fbc4dc9b907a6e59a15599c50b3