fix flaky unit test by removing un-needed waitForElementToBeRemoved (#45291)

frontend/src/metabase/home/components/EmbedHomepage/tests/common.unit.spec.tsx

@@ -204,8 +204,6 @@ describe("EmbedHomepage (OSS)", () => {
         source: "embedding-homepage-dismiss",
       });
 
-      await waitForElementToBeRemoved(() => queryFeedbackModal());
-
       expect(
         screen.getByText("Your feedback was submitted, thank you."),
       ).toBeInTheDocument();