jsondesc: Disallow unknown properties

This helps to catch typos made in drafting core device schemata.
For instance, previously typo'ing `"edge_counter": true` as
`"edge_counters": true` would lead to it silently being ignored.

This required switching to a (meta-)schema version more recent by
one release, as unevaluatedProperties is not supported in draft-7
yet.

artiq/coredevice/coredevice_generic.schema.json

@@ -1,6 +1,6 @@
 {
     "$id": "https://m-labs.hk/kasli_generic.schema.json",
-    "$schema": "http://json-schema.org/draft-07/schema#",
+    "$schema": "https://json-schema.org/draft/2019-09/schema",
     "title": "Kasli variant description",
     
     "type": "object",
@@ -166,6 +166,7 @@
                 }
             },
             "required": ["type"],
+            "unevaluatedProperties": false,
             "allOf": [{
                 "title": "DIO",
                 "if": {

artiq/coredevice/jsondesc.py

@@ -1,6 +1,6 @@
 from os import path
 import json
-from jsonschema import Draft7Validator, validators
+from jsonschema import Draft201909Validator, validators
 
 def extend_with_default(validator_class):
     validate_properties = validator_class.VALIDATORS["properties"]
@@ -23,7 +23,7 @@ schema_path = path.join(path.dirname(__file__), "coredevice_generic.schema.json"
 with open(schema_path, "r") as f:
     schema = json.load(f)
 
-validator = extend_with_default(Draft7Validator)(schema)
+validator = extend_with_default(Draft201909Validator)(schema)
 
 def load(description_path):
     with open(description_path, "r") as f: