Add information about command path and version of flex in meson output

2023-07-03 22:29:24 Michael Paquier (michael-kun) Closed in commitfest 2023-07 with status: Committed 2023-07-03 22:29:24 Michael Paquier (michael-kun) Changed committer to michael-kun 2023-07-03 06:34:57 Peter Eisentraut (petere) New status: Ready for Committer 2023-07-03 06:34:51 Peter Eisentraut (petere) Added petere as reviewer 2023-04-13 00:21:44 Michael Paquier (michael-kun) Changed authors to Michael Paquier (michael-kun) 2023-04-13 00:21:44 Michael Paquier (michael-kun) Changed targetversion to 17 2023-04-13 00:21:34 Michael Paquier (michael-kun) Attached mail thread ZDT3FbmrjBuBthmR@paquier.xyz 2023-04-13 00:21:34 Michael Paquier (michael-kun) Created patch record