feat: automatically advance fake timers in Vitest

[TrevorBurnham]

This PR adds automatic detection of fake timers from both Jest and Vitest, eliminating the need for users to manually configure advanceTimers when using vi.useFakeTimers() or jest.useFakeTimers().

Fixes #1115

Problem

When using Vitest with fake timers, userEvent would timeout because it wasn't advancing the fake timers. Users had to use workarounds like:

globalThis.jest = {
  advanceTimersByTime: vi.advanceTimersByTime.bind(vi),
}

This happened because userEvent only knew about Jest's timer APIs, not Vitest's.

Solution

Automatic detection of both Jest and Vitest fake timers:

1. New timerDetection.ts utility - Detects which testing framework's fake timers are active by checking for globalThis.jest or globalThis.vi
2. Updated wait.ts - When advanceTimers isn't manually configured, automatically detects and uses the appropriate timer advancement function
3. Fully backward compatible - Manual configuration still takes precedence over auto-detection

When both Jest and Vitest globals are present (unlikely but possible), Jest takes precedence. This maintains consistency with existing behavior.

Before

test('button click', async () => {
  vi.useFakeTimers()
  globalThis.jest = {
    advanceTimersByTime: vi.advanceTimersByTime.bind(vi),
  }
  const user = userEvent.setup()
  await user.click(button) // Would timeout without workaround
})

After

test('button click', async () => {
  vi.useFakeTimers()
  // No workaround needed! ✨
  const user = userEvent.setup()
  await user.click(button) // Works automatically
})

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