`RemoveRolesFromCompositeAsync` uses strange serialisation and fails

[AShtifanovBK]

hi,
i have noticed, that this method is using some strange serialisation that is nowhere used in the project:

Keycloak.Net/src/Keycloak.Net/RolesById/KeycloakClient.cs

Line 54 in 5870da2

.SendJsonAsync(HttpMethod.Delete, new CapturedJsonContent(_serializer.Serialize(roles)))

and this method fails due to this, i suppose.

Good that there is another method RemoveCompositesFromRoleAsync which still works:

Keycloak.Net/src/Keycloak.Net/Roles/KeycloakClient.cs

Line 81 in 5870da2

.SendJsonAsync(HttpMethod.Delete, roles)