tmux: disable utf8proc on 32bit platforms

Currently the build fails with incompatible pointer types. We could
patch around this, but it doesn't seem worth it. Technically, some 32bit
platforms (other than i686-linux) could define their wchar_t in a way
that is compatible with utf8proc, but we don't have great test coverage,
so I'm being generous here with the check.

pkgs/by-name/tm/tmux/package.nix

@@ -10,7 +10,8 @@
   runCommand,
   withSystemd ? lib.meta.availableOn stdenv.hostPlatform systemd,
   systemd,
-  withUtf8proc ? true,
+  # broken on i686-linux https://github.com/tmux/tmux/issues/4597
+  withUtf8proc ? !(stdenv.hostPlatform.is32bit),
   utf8proc, # gets Unicode updates faster than glibc
   withUtempter ? stdenv.hostPlatform.isLinux && !stdenv.hostPlatform.isMusl,
   libutempter,