ci(electron): disable failing all jobs if one fails

The electron pipeline is prone to spurious failures, and with the
addition of rerunning only failed jobs, is easier to manage if flaked
jobs are just restarted.

Author: kattrali

.github/workflows/test-electron.yml

@@ -7,6 +7,7 @@ jobs:
 
     runs-on: ${{ matrix.os }}
     strategy:
+      fail-fast: false
       matrix:
         electron: [ '^12.0.0', '^20.0.0' ]
         node-version: [12, 14]