We know we have deprecations functions, and they require a major work
as porting to gtk4.
That's truly a different task to what we are doing every day, and the
multiple warnings obscure all real warnings to the task that is
relevant at that point.

This is making contributors skip the warnings, rather than actually look
at them.

For that, ignore deprecation warnings for now until someone wants to
work in the gtk4 port, and we also assume you read the documentation
when introducing new code in order to avoid deprecations.