Libera Lean is a Liberation[1] derived font, with glyphs subset created from
Liberation 1.7[2] font. It's built in the PoDoFo resource repository[3]

[1] https://github.com/liberationfonts/liberation-fonts
[2] https://github.com/liberationfonts/liberation-1.7-fonts
[3] https://github.com/podofo/podofo-resources/tree/master/Std14Fonts/LiberaLean/Src