Bug#1111506: lintian: Document that override_dh_auto_test-does-not-check-DEB_BUILD_OPTIONS is erroneously raised in compat >= 13

[Gioele Barabucci <gioele@svario.it>]

Package: lintian
Version: 2.122.0
Tags: patch

Dear lintian maintainers,

the warning `override_dh_auto_test-does-not-check-DEB_BUILD_OPTIONS` 
should not be emitted when debhelper compat >= 13 is used, but it still 
is. The bug that tracks this issue is <https://bugs.debian.org/950455>.

Given that this issue has persisted for a long time, it makes sense to 
document it.

A MR that adds a link to the bug can be found at 
<https://salsa.debian.org/lintian/lintian/-/merge_requests/598>.

Regards,

--
Gioele Barabucci