message: chore: deprecate observable symbol export
  resolves
diff: -/** Symbol.observable or a string "@@observable". Used for interop */
  +/**
  + * Symbol.observable or a string "@@observable". Used for interop
  + *
  + * @deprecated We will no longer be exporting this symbol in upcoming versions of RxJS.
  + * Instead polyfill and use Symbol.observable directly *or* use https://www.npmjs.com/package/symbol-observable
  + */
  export const observable: string | symbol = (() => (typeof Symbol === 'function' && Symbol.observable) || '@@observable')();
  