Switch GraphQL variables code editor to json linting (#4756)

Author: claypowers

packages/bruno-app/src/components/RequestPane/GraphQLVariables/index.js

@@ -64,7 +64,7 @@ const GraphQLVariables = ({ variables, item, collection }) => {
         font={get(preferences, 'font.codeFont', 'default')}
         fontSize={get(preferences, 'font.codeFontSize')}
         onEdit={onEdit}
-        mode="javascript"
+        mode="application/json"
         onRun={onRun}
         onSave={onSave}
         enableVariableHighlighting={true}