stage-cypress-tests: Replace use of cypress-cloud by cypress-split

Cypress >= 13.3 blocked the use of sorry-cypress and cypress-cloud in the cypress binary so we can no longer use these tools to execute parallel cypress tests on Jenkins.

Fortunately, it exists another tool called cypress-split that can be used for the same purpose without relying on a tests orchestration server.

So replace the use of sorry-cypress and cypress-cloud by cypress-split to still benefit of parallel cypress tests in CI jobs for swh-web.

This change also brings a huge speedup for parallel cypress tests execution as communication with a tests orchestration server is no longer required.

I hacked the swh-web pipeline on our production Jenkins with those changes and cypress tests can still be successfully executed in parallel.

Depends on swh/devel/swh-web!1186 (merged)