Programmatic exemptions for lintian are obsolete

[Felix Lechner <felix.lechner@lease-up.com>]

Hi,

Traditionally, we exempted Lintian from its own checks when the test
suite triggered a tag. With this commit, it should no longer be
necessary:

    https://salsa.debian.org/lintian/lintian/-/commit/4f4654ddfd2841f5440a83bc3f30b6091b10986c

The commit automatically exempts Lintian's test suite. All other tags
are probably real.

Please do not exempt Lintian programmatically any more. It leads to
ridicule and an image problem on IRC.

Please use visit_patched from Lintian::Check instead. It's new, but I
think it works.

The new setup was tested with a full build and self-examination by
Lintian in a testing chroot, which produced no tags.

Kind regards
Felix Lechner