build: update to yarn@1.21.1 (#34384)

This updates yarn throughout the monorepo for both build and CI.

PR Close #34384

aio/tools/examples/shared/package.json

@@ -13,7 +13,7 @@
   "//engines-comment": "Keep this in sync with /package.json and /aio/package.json",
   "engines": {
     "node": ">=10.9.0 <13.0.0",
-    "yarn": ">=1.17.3 <2"
+    "yarn": ">=1.21.1 <2"
   },
   "keywords": [],
   "author": "",
@@ -58,8 +58,8 @@
     "@types/express": "^4.0.35",
     "@types/jasmine": "~2.8.8",
     "@types/jasminewd2": "^2.0.4",
-    "@types/jquery":"3.3.28",
-    "@types/node":"~12.12.14",
+    "@types/jquery": "3.3.28",
+    "@types/node": "~12.12.14",
     "canonical-path": "1.0.0",
     "concurrently": "^3.0.0",
     "http-server": "^0.11.1",