Add optional dependencies for Cantor CI
We are providing Gitlab CI for Cantor (https://invent.kde.org/kde/cantor/-/merge_requests/1) but we would like to add the follow optional dependencies:
-- The following OPTIONAL packages have not been found: * LibSpectre, A PostScript rendering library, <https://www.freedesktop.org/wiki/Software/libspectre/> Support for rendering EPS files in Cantor * Qalculate, A multi-purpose desktop calculator with support for customizable functions, units and arbitrary precision., <https://qalculate.github.io/> Backend to use Qalculate with Cantor. * PythonLibs (required version >= 2.7), A powerful dynamic programming language., <https://www.python.org/> Backend to use Python 2 with Cantor. * LuaJIT, A lightweight, extensible programming language (luajit implementation)., <https://www.lua.org/> Backend to use Lua (luajit2) with Cantor. * Julia, A high-level, high-performance dynamic programming language for technical computing, <https://julialang.org/> Backend to use Julia with Cantor.
How can we add these dependencies? Is there any documentation about how to do it?