Updating Widelands to 1.0

Dear Games Team,

Release 1.0 of Widelands is now 9 months old. There had been 2 bug reports
requesting an update: #992626 and #998688 without any replies. I also tried
submitting a bug (#1005370) for the watch file which became broken by the
new version scheme of Widelands.

It would be hard for users if bookworm missed 1.0, because 1.1 will have
many changes that will break savegame compatibility with build-21 (current
Debian version).

I had a look at the salsa page, but it convinced me that this is not a task
for someone like me who had never worked on a Debian package before.
Importing a new upstream release seems daunting in itself, but then there's
the epoch bump and the need for a new watchfile.

The update in itself shouldn't be a big deal: I had been able to update the
flatpak packaging just by bumping version numbers with zero previous
knowledge of flatpak manifests. The build system didn't change, there are
no new dependencies in 1.0 and Widelands is not picky about library
versions at all.

Could someone have a look at this package, please?

Thank you,
T.A.