deps: pin circular-json@0.5.5 to avoid output deprecate message (#3023)

the author of `circular-json` recommended `flatted` to replace `circular-json`
but `flatted`'s output is too different with JSON.stringify which don't fit our needs

.autod.conf.js

@@ -27,5 +27,9 @@ module.exports = {
     '@types/koa-router',
     '@types/urllib',
   ],
+  keep: [
+    // circular-json > 0.5.5 will output some deprecate message, and we don't want to use flatted
+    'circular-json',
+  ],
   test: 'scripts',
 };

package.json

@@ -20,7 +20,7 @@
     "accepts": "^1.3.5",
     "agentkeepalive": "^3.5.1",
     "cache-content-type": "^1.0.1",
-    "circular-json": "^0.5.5",
+    "circular-json": "0.5.5",
     "cluster-client": "^2.1.1",
     "debug": "^4.0.1",
     "delegates": "^1.0.0",