I need to try and patch around Qts buildsystem to keep #21778 moving
along (the issue being that even when you tell Qt to build using
Clang on Linux, it still calls out to GCC, breaking our ability to have
a macOS release build env that doesn't have a GCC toolchain installed,
and thus no ld binary).
Before trying to patch Qt any further, update to the latest LTS
release, and update the current patch set.