chore(babel): add @babel/plugin-proposal-nullish-coalescing-operator (#8492)

.babelrc

@@ -7,6 +7,7 @@
     "@babel/plugin-proposal-export-namespace-from",
     "@babel/plugin-proposal-class-properties",
     "@babel/plugin-proposal-logical-assignment-operators",
+    "@babel/plugin-proposal-nullish-coalescing-operator",
     "@babel/plugin-proposal-optional-chaining",
     "@babel/plugin-transform-modules-commonjs"
   ],