Disable F-ligas on monotype-spaced scripts#3

Hi, Silke-san, @silkeh I am using gratefully your great work here on my daily happy TeXing! As you can see the following LaTeX document, the virtual font of monotype-spaced family has enabled F-ligatures. Do you have the plan that you provide it with no F-ligatures? Indeed, we may generate it by giving some command line options related to ligatures for otftotfm program. ``` %#!pdflatex \documentclass{article}\listfiles \usepackage{sourcecodepro} \usepackage{alltt} \begin{document} We currently use \ttdefault\ as \texttt{\textbackslash ttdefault} default. We can see that the \ttdefault\ virtual font has F-ligas below. \noindent \texttt{fi fl ff ffi ffl} \begin{verbatim} file_name fl ff ffi ffl \end{verbatim} \begin{alltt} file_name fl ff ffi ffl f{}ile_name f{}l f{}f ff{}i ff{}l \end{alltt} \end{document} ```