[tlbuild] luatex rebuild from branch2023

[Karl Berry]

Hello TL builders,

Some issues have been found in luatex (obscure ways to work around some
security features; thanks to Max Chernoff), so we need to rebuild.
Luigi has committed fixes to the sources, and labeled the new luatex
version 1.17.0. All variants of the engine are affected, so there are
four binaries to update:
  luatex luahbtex luajitex luajithbtex

FYI, the change that's most likely to be noticeable is that the socket
library is now disabled by default; a new option --socket enables it, as
well as --shell-escape (not --shell-restricted). In addition, the mime
library is now always available, and new functions os.socketsleep and
os.socketgettime are also always available. I will put a summary at
https://tug.org/texlive/bugs.html after the binaries are committed.

We need to rebuild from branch2023 (committed in r66984),
because too many unrelated changes have been made to the trunk.

You can retrieve the sources from the branch to the cwd 
with subversion:
  svn co svn://tug.org/texlive/branches/branch2023/Build/source .
or with rsync:
  rsync -a --delete --exclude=.svn --exclude=Work --exclude=inst \
        tug.org::tlbranch .

Then ./Build or whatever you normally do should suffice. If you want to
skip compiling all the utilities,
  ./Build --disable-all-pkgs --enable-web2c
should build only the engines. (You can further add --disable-xetex,
etc., if you feel the need.) There is no harm to building everything,
though, which is probably easiest of all :).

Feel free to commit the four binaries yourself if you wish, or send (a
url to) them to me. The normal autobuilds will not work here, since they
are from the trunk, so Mojca and Norbert, please let me know where to
get them.

I've already committed x86_64-linux (built on centos7).

The new binaries do not, so far as I know, even require a .fmt rebuild,
though tlmgr will make that happen anyway as a matter of course with a
normal installation.

Thanks. --karl