Replace get_event_loop() with get_running_loop() for asyncio compatibility

Hello, I got `DeprecationWarning: There is no current event loop` when using `dominate v2.9.1` with Python 3.10 or newer. ref: https://github.com/thombashi/pytablewriter/issues/66 According to the [official Python 3.10 document](https://docs.python.org/3.10/library/asyncio-eventloop.html#asyncio.get_event_loop): > In Python versions 3.10.0–3.10.8 and 3.11.0 this function (and other functions which use it implicitly) emitted a DeprecationWarning if there was no running event loop, even if the current loop was set on the policy. In Python versions 3.10.9, 3.11.1 and 3.12 they emit a DeprecationWarning if there is no running event loop and no current loop is set. In some future Python release this will become an error. And it was [deprecated in Python 3.12](https://docs.python.org/3.13/library/asyncio-eventloop.html#asyncio.get_event_loop): >Deprecated since version 3.12: Deprecation warning is emitted if there is no current event loop. In some future Python release this will become an error. The document suggests using the `get_running_loop()` function instead of `get_event_loop()` function. This will resolve: https://github.com/Knio/dominate/issues/198