[py] Update type annotation to include WebElement

This adds `WebElement` to the type annotation for the `frame_to_be_available_and_switch_to_it` function in the `expected_conditions` module.

Author: cgoldberg

py/selenium/webdriver/support/expected_conditions.py

@@ -485,7 +485,7 @@ def _predicate(driver: WebDriverOrWebElement):
     return _predicate
 
 
-def frame_to_be_available_and_switch_to_it(locator: Union[Tuple[str, str], str]) -> Callable[[WebDriver], bool]:
+def frame_to_be_available_and_switch_to_it(locator: Union[Tuple[str, str], str, WebElement]) -> Callable[[WebDriver], bool]:
     """An expectation for checking whether the given frame is available to
     switch to.