E2E Tests parallel execution

[CDimonaco]

Description

This pr splits the cypress tests execution across multiple CI jobs, we use the cypress-split plugin.
This PR does not fix any issue on flakiness or test logic, it just speeds up the execution of test pipeline.

[gagandeepb]

Thanks for this! I wonder what is the expected/observed speed-up with these changes ?

[CDimonaco]

Thanks for this! I wonder what is the expected/observed speed-up with these changes ?

That's a good question! I observed an increase of speed of about 5 to 7 minutes, but this is just the first step, when we refactor the e2e tests, in order to make them less flaky and without some useless costly operations (mostly photofinish dump when not needed), this pr should make a lot more sense

[arbulu89]

Perfect! Really really appreciated!
Just a comment about putting the 4 as a variable

PD: I don't know if we would need some change in the artifact upload in failure cases, otherwise they might overwrite. Maybe we can add some sort of index to the folder name

[arbulu89]

Can we have this 4 in some variable on top?
So we can change if needed, as it is used in 2 places

[balanza]

Also: where does this number come from? Should it be the number of cores?

[balanza]

question: ‏As far as I get it, this action just provides a range for enumeration, right? Like you say 4 and it spits [1,2,3,4]

[balanza]

question: ‏Where do those variables come out? Shouldn't be something like strategy.matrix... or prepare.output.matrix...?

[balanza]

Thank you @CDimonaco, this PR is very valuable for me as it barely halves the CI execution time.

There are some unanswered questions in comments, besides that I think we should merge.