maintain-kubeusers: adapt to lima-kilo
Let's assume the devel environment for maintain-kubeusers is lima-kilo.
Introduce a helper script to record VCR cassettes, and refresh the README with the new instructions.
While at it, refresh tests themselves, to account for lima-kilo.
Bug: T363482 Signed-off-by: Arturo Borrero Gonzalez aborrero@wikimedia.org