How to scroll to the bottom of an infinite page using scrapy-playwright python

The page I'm trying to scrape loads more items as you scroll down. I know how to make playwright scroll, I'm using a coroutine like this currently

PageCoroutine("evaluate", "window.scrollBy(0, document.body.scrollHeight)")

which when paired with another

wait_for_selector

coroutine where the selector is the id of the last item on the page works. My issue is the last item changes often and so I can't rely on it.

How can I tell scrapy/playwright to just keep scrolling until the bottom without needing to identify an element at the bottom?

Thanks

Here is my spider incase it helps:

import scrapy
from scrapy_playwright.page import PageCoroutine


class MySpider(scrapy.Spider):
    name = 'my_spider'

    def start_requests(self):
        yield scrapy.Request(
            'my-url',
            meta={
                'playwright': True,
                'playwright_include_page': True,
                'playwright_page_coroutines': [
                    PageCoroutine("evaluate", "window.scrollBy(0, document.body.scrollHeight)"),
                    PageCoroutine("wait_for_selector", "{item_at_bottom}"),
                ]
            }
        )

    async def parse(self, response):
        pass
        # parses my content