Bug#996077: gnome-shell-mailnag: does not declare compatibility with GNOME Shell 41

[Simon McVittie <smcv@debian.org>]

Package: gnome-shell-mailnag
Version: 40.0-1
Severity: normal
Tags: bookworm sid
User: pkg-gnome-maintainers@lists.alioth.debian.org
Usertags: gnome-shell-41

The metadata.json for this extension doesn't declare compatibility with
GNOME 41. I don't know whether the actual code will need changes or not:
the conservative assumption is that it probably will (so please test).
gnome-shell 41 should be available in experimental soon.

In versions of GNOME Shell up to 3.38, metadata.json didn't matter much,
because validation of extensions' metadata against the installed Shell
version was disabled by default; but since GNOME 40 the default has changed
back to enabling the version check by default, in an effort to avoid
issues caused by outdated extensions remaining enabled. As a result,
GNOME Shell extensions in bookworm should probably have a dependency like:

    Depends: gnome-shell (>= x), gnome-shell (<< y~)

where x and y are set according to metadata.json.
gnome-shell-extension-caffeine is a good example of this technique.

When we do the GNOME Shell 41 transition, hopefully soon, we will have
to either update this extension or remove it from testing. It would be
useful to get a fixed version into experimental.

Thanks,
    smcv