ci chore: respond to macos job failures

[lread]

Symptom

For many macOS jobs I am seeing failures like this:

npm ERR! code EACCES
npm ERR! syscall open
npm ERR! path /Users/runner/.npm/_cacache/tmp/5c0e8b0b
npm ERR! errno -13
npm ERR! 
npm ERR! Your cache folder contains root-owned files, due to a bug in
npm ERR! previous versions of npm which has since been addressed.
npm ERR! 
npm ERR! To permanently fix this problem, please run:
npm ERR!   sudo chown -R 501:20 "/Users/runner/.npm"

npm ERR! A complete log of this run can be found in:
npm ERR!     /Users/runner/.npm/_logs/2023-02-16T18_29_41_010Z-debug-0.log
Error: Process completed with exit code 243.

Guesses

GitHub is rolling out a new macOS image.
It includes node 18 (previous version was node 16).
Some rules might have changed.

The /Users/runner/.npm dir does not seem to be related to any caching I have requested.
The workflow only requests that ./node_modules be cached.

The cljs tests rely on cljs-test-runner which uses doo which relies on karma for browser testing.
Karma is installed with sudo npm install karma-cli -g.
So that might be related? Dunno.
Can try to install and refer to karma locally instead of globally.