[js-core] Look into `Promise.withResolvers`

[ersimont]

Would this allow any improvement to Deferred? https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/withResolvers

[ersimont]

Not currently available in the default TS lib scaffolded w/ Angular. (Currently v17, using TS 5.2)

[ersimont]

Still not available in v20, TS 5.8.