Bump yarn to 4.6.0 (#575)

.yarnrc.yml

@@ -12,4 +12,4 @@ logFilters:
 
 nodeLinker: node-modules
 
-yarnPath: .yarn/releases/yarn-4.5.1.cjs
+yarnPath: .yarn/releases/yarn-4.6.0.cjs

package.json

@@ -6,7 +6,7 @@
   },
   "homepage": "https://github.com/polkadot-js/wasm#readme",
   "license": "Apache-2.0",
-  "packageManager": "yarn@4.5.1",
+  "packageManager": "yarn@4.6.0",
   "private": true,
   "repository": {
     "type": "git",