Here's some notes for anyone who wants to build mcrouter on Ubuntu 22.04

1. Replace mcrouter/m4/ax_python_devel.m4 by the latest version from https://github.com/autoconf-archive/autoconf-archive/blob/master/m4/ax_python_devel.m4
2. Update gtest version number in mcrouter/scripts/recipes/gtest.sh.
3. Remove -j3 from mcrouter/scripts/get_and_build_by_make.sh
4. Change apt packages

See my fork for detail: 93db39f