libsynctex version check for new API doesn't check for upstream version
When zathura was updated to support libsynctex's new API it was made to look for libsynctex version 2.0.0 to decide whether to use the old or new API, but TeXLive did not bump the libsynctex version to 2.0.0, instead itcat is reported as 1.21.0.
Debian however contains their own downstream patch to make it report 2.0.0, but that is not upstream behavior.
https://github.com/TeX-Live/texlive-source/blob/cf44eb85489078e69a724b2b46d0000ac0691c46/texk/web2c/synctexdir/synctex.pc.in https://github.com/TeX-Live/texlive-source/blob/cf44eb85489078e69a724b2b46d0000ac0691c46/texk/web2c/synctexdir/synctex_parser_version.txt