Summary:
Turns out, we don't have any tests that _actually_ depend on Electron. What is more, the one test suite that was still left was actually failing for a long time, but somehow CI didn't pick and reported that :-P.
Note that I dropped the file `xplat/sonar/scripts/facebook/lego/run-sc-yarn-targets-with-electron.sh` entirely, as it appeared unused
Reviewed By: nikoant
Differential Revision: D22434441
fbshipit-source-id: 34df79a580a64904116ae93069bbc8fafc53d9d0
