Upgrade dist-mips*-linux to ubuntu:22.04 + crosstool-ng These have no change in compatibility, still Linux 4.4 and glibc 2.23. The main motivation for upgrading is that LLVM 16 will require at least GCC 7.1. Using crosstool-ng lets us choose our own toolchain versions, and then the Ubuntu version doesn't matter so much, just for the host compilation while we cross-compile.