test: Update toolbar playwright tests

* Please replace these with locator expectations. We are not guaranteed that these will work within two hundred milliseconds. https://github.com/posit-dev/py-shiny/blob/c2e4b20421f75bd140d28876e6556ea8291a0277/tests/playwright/shiny/components/toolbar/toolbar_select/test_toolbar_select.py#L315 * Please do not access html unless you have verified the object exists with an expectation just before. When possible, use locator expect methods, rather than adhoc testing https://github.com/posit-dev/py-shiny/blob/c2e4b20421f75bd140d28876e6556ea8291a0277/tests/playwright/shiny/components/toolbar/toolbar_select/test_toolbar_select.py#L316 * Please use `shiny.playwright.expect.expect_not_to_have_attribute()` to verify that the attribute is missing. (Explore other methods in our expect module for other helpers 😃 ) https://github.com/posit-dev/py-shiny/blob/c2e4b20421f75bd140d28876e6556ea8291a0277/tests/playwright/shiny/components/toolbar/toolbar_select/test_toolbar_select.py#L339-L341