🧹 Temporarily disable rights statement requirement

This commit will temporarily disable rights statement as a required
field until we finish migrations.  Then we can deal with the object in
question more easily.

Author: kirkkwang

config/metadata/generic_work_resource.yaml

@@ -46,7 +46,7 @@ attributes:
     type: string
     multiple: true
     form:
-      required: true
+      required: false
       primary: true
     index_keys:
       - "rights_statement_sim"