Update pxt.json

MainInit · web-flow · commit b711d3842550 · 2023-09-11T12:00:35.000+08:00
diff --git a/pxt.json b/pxt.json
@@ -20,7 +20,7 @@
     ],
     "public": false,
     "targetVersions": {
-        "target": "5.0.12",
+        "target": "4.0.18",
         "targetId": "microbit"
     },
     "supportedTargets": [
