[luatex] Identifying why LuaTeX 2023 is slower than LuaTeX 2022

[Karl Berry]

    Karl, could you please rebuild the TL LuaTeX binaries with -O3 for
    x86_64-linux? 

I committed (r68135) the binaries from Norbert's last autobuild on
github for TL23:
https://github.com/TeX-Live/texlive-source/releases/download/build-svn66984/texlive-bin-x86_64-linux.tar.gz

The version number/devid were the same. I hope this was the right thing.
--thanks, karl.