test_runner: MockTimers does not support Temporal

### What is the problem this feature solves? As of Node.js 26, `Temporal` is enabled by default ([#62526](https://github.com/nodejs/node/pull/62526)), and the platform is in the process of growing Temporal support across its APIs ([#57891](https://github.com/nodejs/node/issues/57891), [#63154](https://github.com/nodejs/node/issues/63154), [#63312](https://github.com/nodejs/node/issues/63312)). One gap that doesn't seem to be tracked anywhere yet: `node:test`'s `MockTimers` has no way to control `Temporal.Now`. `MockTimers.enable({ apis })` accepts `'setTimeout' | 'setInterval' | 'setImmediate' | 'Date'`. Passing `'Temporal'` (or any Temporal-related token) throws `ERR_INVALID_ARG_VALUE`. There is also no documented way to advance / freeze `Temporal.Now.instant()`, `Temporal.Now.zonedDateTimeISO()`, etc. via the mock clock. Concretely, this means any code that reads "now" via `Temporal.Now` instead of `Date.now()` can't be tested deterministically with the built-in test runner. With Temporal now being the recommended way to do date/time work, this is increasingly the common case — code migrating away from `Date` loses its ability to use `MockTimers` for time-based assertions. ### Repro ```js import { mock } from "node:test"; mock.timers.enable({ apis: ["Temporal"] }); // TypeError [ERR_INVALID_ARG_VALUE]: The property 'options.apis' must be one of: // ['setTimeout', 'setImmediate', 'setInterval', 'Date'] mock.timers.enable({ apis: ["Date"], now: 0 }); console.log(new Date().toISOString()); // 1970-01-01T00:00:00.000Z (mocked) console.log(Temporal.Now.instant().toString()); // current real time (NOT mocked) ``` ### What is the feature you are proposing to solve the problem? Extend `MockTimers` so that, when `Temporal` is in the `apis` list, the following are tied to the mock clock: - `Temporal.Now.instant()` - `Temporal.Now.zonedDateTimeISO(timeZone?)` - `Temporal.Now.plainDateTimeISO(timeZone?)` - `Temporal.Now.plainDateISO(timeZone?)` - `Tempo…