pd-lua update to 0.11.4
This updates pd-lua to 0.11.4, cf. https://github.com/agraef/pd-lua/releases/.
pd-lua now uses the latest pd-lib-builder and includes lua as a submodule, so building it as a part of purr-data becomes a lot easier. Most notably, Lua 5.4 is linked statically from lua/onelua.c, so Lua isn't needed as a build or runtime dependency any more and the resulting external will use exactly the same Lua version across different platforms.
Also, the latest pd-lua sports various important bugfixes and documentation updates.