community/qt5-qttools: fix building of -dev subpackage
The -dev subpackage failed to rebuild on one of the builders due to amove being unable to find QDoc files. QDoc was not enabled because libclang and the required LLVM version were not found during configuration.
Due to the switch to LLVM 19 as the new default, add the non-default version to $PATH
so it can be detected.
Edited by mio