Clean-up ToDos added in our ESR 78 preparation
We have #40014 to address the specific lucetc/wasi-sdk shortcuts I took for getting the toolchains ready for nightly builds.
There is more to clean-up, though, for having them alpha ready. This is the issue for that task.
On the top of the list is finding a better place for our compiler-rt cross-compilation for macOS. This relates to #31517, too.