sylva-units failing unittest on lookup SylvaUnitsRelease

$ helm unittest -t JUnit -o report.xml charts/sylva-units
 ..
executing "gotpl" at
 <lookup "unitsoperator.sylva/v1alpha1" "SylvaUnitsRelease" .Release.Namespace "">
 error calling lookup: coding error:
 you must register resource to list kind for every resource you're going to LIST when creating the client.  See NewSimpleDynamicClientWithCustomListKinds or register the list into the scheme: /, Resource= out of map[helm.toolkit.fluxcd.io/v2, Resource=helmreleases:HelmReleaseList]

must have been introduced by !6341 (merged) ... although I can't see why the test was passing in that MR... 🤔

/cc @feleouet