Fcitx5 5.1.8

[Weng Xuetian]

Hi,
This is mainly a bug fixing release. We are focusing on the code
health for this release with the help of coverity. Also kudos to Chen
shijie for helping fix issues found with the static analysis tool.

As for packagers, please note that now Qt6 is the default option. The
change is to make it align with the Plasma 6 release.

If your distribution does not provide Plasma 6, you may want to pass
-DUSE_QT6=Off to the package. If your distribution does provide Plasma
6, make sure you build fcitx5-configtool with Plasma/KF6 packages so
it can be integrated to the Plasma6's systemsettings correctly.

fcitx5-keyman 1.1.0 now requires keyman 17 to build since they upgrade
their API.

Thanks!