feat: convert heading challenge test to Playwright

[Sembauke]

Checklist:

• I have read and followed the contribution guidelines.
• I have read and followed the how to open a pull request guide.
• My pull request targets the main branch of freeCodeCamp.
• I have tested these changes either locally on my machine, or GitPod.

Closes #XXXXX

[huyenltnguyen]

I think we need to include the Cypress file deletion in this PR, too?

[huyenltnguyen]

Could we simplify the test with:

await page.goto('this-page')

await page.waitForURL('that-page')
await expect(page.getByRole('heading', { name: 'Title of that page' })).toBeVisible()

?

[Sembauke]

To keep consistency, I think we should go with

      await page.goto(input);
      await expect(page).toHaveURL(new RegExp(`${expected}/?`));

[Sembauke]

I am going to block this one as #54897 does the same thing and I want to merge it in to that spec file.