Sunset CPAN::Audit::DB in favor of CPANSA::DB

[briandfoy]

• Choose some EOL date for CPAN::Audit::DB
• add a warning to CPAN::Audit and cpan-audit if that's the database it would choose
• release a new CPAN::Audit on the EOL date that does not use CPAN::Audit::DB
• change cpan-security-advisories to not generate it

See briandfoy/cpan-security-advisory#376

[nrdvana]

Why not just change the module to

package CPAN::Audit::DB;
use CPANSA::DB;
sub db { CPANSA::DB::db() }

and leave it as a back-compat shim?

[briandfoy]

The idea is that there is a single file that you'd transfer to the place where you'd do the analysis. Making it a shim makes that a two file thing. Along with that, it's just the wrong name to use, so eventually people have to stop using it.