[Feature]: support signal in waitFor* APIs

[tmkx]

🚀 Feature Request

Many Playwright ⁠waitFor* APIs support a ⁠timeout option, which works well for fixed upper bounds. A complementary capability would be support for ⁠AbortSignal, so callers can cancel an in-flight wait based on external application state.

Example

A consistent API shape could look like this wherever ⁠timeout is already supported:

await locator.waitFor({
  state: 'visible',
  timeout: 30_000,
  signal,
});

await page.waitForURL('**/dashboard', {

Motivation

This would make Playwright waiting APIs easier to compose with:

• shared cancellation across multiple concurrent operations
• higher-level test orchestration
• user-defined deadlines and cascading cancellation
• integration with standard Web Platform and Node.js cancellation patterns