Fix end to end test - Publishing Flow

[timarney]

Feature Description

Test is timing out waiting for media-modal selector

Publishing Flow › should guide me towards creating a new post to embed my story with poster
    TimeoutError: waiting for selector `.media-modal` failed: timeout 3000ms exceeded
      70 |     await expect(page).toClick('button[aria-label="Poster image"]');
      71 |
    > 72 |     await page.waitForSelector('.media-modal', {
         |                ^
      73 |       visible: true,

Alternatives Considered

Additional Context