Bug#1020304: pygobject: please backport to bullseye

[Martin]

Source: pygobject
Version: 3.42.2-2
Severity: wishlist

The next version of Gajim will depend on a newer python3-gi than is
available in Debian 11, because of:

> 3.42.0 - 2021-09-19
> * Expose GObject.Object.run_dispose() :issue:`470`

Therefore, I like to backport pygobject to be able to continue the
line of backports of Gajim for users of Debian stable.

The backport seems to be trivial, no further dependencies nor patches
are needed. If nobody objects, I'll upload to bpo soon.