DBI Bundle::DBD::Foo modules

DBI states that DBD drivers should provide a Bundle::DBD::Foo to
leverage the CPAN 'Bundle'  mechanism. (ref:
https://metacpan.org/module/DBI::DBD#lib-Bundle-DBD-Driver.pm)

As a result many of the DBD driver distributions - such as DBD::Pg,
DBD::mysql, DBD::CSV - provide such a Bundle. Note that DBD::ODBC and
DBD::Oracle do not have a corresponding Bundle.

However the Bundle mechanism, which is described at
https://metacpan.org/module/CPAN#Bundles - is deprecated; dependencies
for DBD drivers can be correctly specified in Makefile.PL, Build.PL
and/or dist.ini

I brought this issue up on #dbi, was pointed to #toolchain , asked
there and they confirmed my assumption that the Bundle:: modules don't
serve any purpose; or at least not anymore, and probably for a *very*
long time already.

It could be that people 'depend' on a Bundle module so I think we
should not remove existing bundles.

my proposal is:

 - Remove the section from DBI documentation that states a DBD should
have a Bundle
 - Update the text in the existing Bundles, which now typically reads
someting along the lines of "This bundle includes all that is needed
to connect with a MySQL server using DBI." to "This file exists for
historical reasons."

Feedback very welcome!
--
Mike