Refactor e2e workflow

[Haarolean]

Issues with e2e-playwright workflow since c10f90e:

1. The previous workflow used to have 3 stages: 'build', 'test', and 'reports'
2. Merge checks used to force 'test' stage as required

TODO:

1. The workflow should contain 'build', 'test' and 'reports' stages
2. One could quickly restart the tests if they previously failed, without having to wait for a full build

use older pre-playwright workflow as a reference: bd7d954