chore: make moddle a peerDependency

Author: nikku

package-lock.json

@@ -53,13 +53,16 @@
     "eslint": "^8.24.0",
     "eslint-plugin-bpmn-io": "^0.16.0",
     "mocha": "^10.0.0",
+    "moddle": "^6.2.0",
     "npm-run-all": "^4.1.5",
     "rollup": "^2.79.1",
     "rollup-plugin-terser": "^7.0.2"
   },
   "dependencies": {
     "min-dash": "^4.0.0",
-    "moddle": "^6.2.0",
     "saxen": "^9.0.0"
+  },
+  "peerDependencies": {
+    "moddle": ">= 6.2.0"
   }
 }