build: downgrade yarn version for Circle CI

nogic1008 · nogic1008 · commit 73eaf6de85cf · 2021-06-16T12:13:23.000+09:00
diff --git a/package.json b/package.json
@@ -3,7 +3,7 @@
   "private": true,
   "engines": {
     "node": ">=10",
-    "yarn": "^1.21.1"
+    "yarn": "^1.17.3"
   },
   "workspaces": {
     "packages": [
