Adding a Model requires "partNumber" and "productLabel" but those attributes should be optional

[jcps07]

Adding a Model in DCL requires fields "partNumber" and "productLabel" but those attributes are Optional in the Basic Information Cluster (Table 11.1.6.3 Attributes from Matter Spec).
Enforcing them in the DCL is not correct.

~$ dcld tx model add-model --vid=0x3000 --pid 1234 --deviceTypeID 1 --productName "ProdName" --from "test-vendor"
Error: required flag(s) "partNumber", "productLabel" not set