Documentation: bug-hunting.rst: remove odd contact information

At the bottom of the bug-hunting.rst file there is a "signature" which
doesn't seem to make much sense.  It seems to predate git, and perhaps
was from an earlier bug report that got copied into the document, but
now makes no sense so remove it.

Cc: greg@wind.rmcc.com
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Alex Shi <alexs@kernel.org>
Cc: Yanteng Si <si.yanteng@linux.dev>
Cc: Hu Haowen <2023002089@link.tyut.edu.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/2025011005-resistant-uncork-9814@gregkh