Jenkins: Automatically create swh-web admin user for cypress tests
In order for @kalpitk to implement cypress tests related to admin features, automatically create an admin user for swh-web when running related Jenkins jobs (similar to rDWAPPS59db5cd69f3a03f6bed96be811bf4821ed500569, setting this up for local cypress tests running).
Migrated from D1819 (view on Phabricator)