Scripts: move ibus-engine-cangjie installation path to libexecdir
- Follow convention of ibus engines implementations.
- All ibus engine implemenations I've installed on Fedora 40 has their binary installed to /usr/libexec now.
- Add extra variable "pkglibexecdir" for the component XML. The variable has to be absolute for the XML to be valid.
- Fix #58 (closed).
Edited by Koala Yeung