This speeds up the CI build, since before it was effectively 1.
Build times on ubuntu-latest are reduced by slightly over 2 minutes.
Note Linux CI runners are defined to have 2 cores and Mac runners 3.
It seems an update to the ubuntu image github uses included pcre2, but
only the 64-bit version.
So since we now force a 32-bit fish but don't force the vendored pcre,
it complains.
Simply force the vendored pcre as well as I don't believe it's worth
it to change the pcre2 detection in this case.
The GitHub documentation states that python3 w/ pip3 is already
installed, and homebrew is slow as molasses (and when it finally runs it
gives a warning about python already being installed and up to date).
This was updated and now always fails, but it always did so - you can
test it with 3.1.2 as well, it's just not happy with the iothread
stuff.
Because it's super easy to test this locally this disables the github
actions test so it doesn't complain *constantly*.
See #7681
