SQLAlchemy 1.3 and 1.4 disagree whether to use
`DBBinary.suites` (SQLA 1.3) or `DBSource.suites` (SQLA 1.4).
Explicitly specify which one to use.

`dcut` is unhappy when it has no name or email address, but this can
happen in some environments like containers. Set the variables to
avoid failures.

The tests for `clone()` fail in Debian bookworm and the function seems
unused.

SQLAlchemy 1.4 raises `IntegrityError` here.

It is done.

For bullseye and bookworm the suitename includes `-security` for the
security archive. This suffix has to be removed when using the
override files from ftp-master where the correspondig suites do not
include this suffix.

Closes: #1027804

Closes: #1029497

This makes the generated documentation more useful when working on DAK
itself.