qt5: Depend on core libxkbcommon (#1851)
qt5: Depend on core libxkbcommon (#1851)

It was moved from homebrew/x11.
LinuxbrewTestBot/homebrew-core,maxim-belkin/homebrew-core,rwhogg/homebrew-core,Linuxbrew/homebrew-core,Linuxbrew/homebrew-core,LinuxbrewTestBot/homebrew-core,maxim-belkin/homebrew-core,rwhogg/homebrew-core