Fcitx 5.0.15

[Weng Xuetian]

Hi all,
It has been a while. In this release we have some important bugfixing
for fcitx5, for stability.

Egl in classicui is dropped due to its buggy (not only the
implementation in fcitx, but potentially cairo-gl). Since more
compositors begin to support zwp_input_method, we'd like to have one
code path that get tested most. This should fix issue on sway without
proper zwp_input_popup_surface_v2 but with cairo-gl enabled.

Another important improvement is to fix the event order delivered on
gtk4. Since gtk4 there is no reliable way for im module to handle dbus
events asynchronously.

Other fixes include fix sd-bus file descriptor handling, this should
fix the issue with fcitx5-wayland-launcher with USE_SYSTEMD=On. And a
potential crash when exiting on wayland with second connection.

Otherwise it's mainly translation updates in other packages. Thanks
for the contribution from translators.

Thanks,
Xuetian