Adds support for CC-BY-NC licenses (#6648)

.github/rsi-schema.json

@@ -79,6 +79,8 @@
          "enum":[
             "CC-BY-SA-3.0",
             "CC-BY-SA-4.0",
+            "CC-BY-NC-3.0",
+            "CC-BY-NC-4.0",
             "CC-BY-NC-SA-3.0",
             "CC-BY-NC-SA-4.0",
             "CC0-1.0"
@@ -180,4 +182,4 @@
       }
    },
    "additionalProperties":true
-}
+}