replace bunx to bun x

[AbdallahAskar1]

What does this PR do?

• Documentation or TypeScript types (it's okay to leave the rest blank in this case)
• Code changes

How did you verify your code works?

[colinhacks]

Why? We use bunx primarily throughout the rest of the docs (this is intentional)

[Jarred-Sumner]

I think we need to fix a bug with symlinking bunx so that people don’t run into issues with it not existing, but that’s not a documentation problem.

Thank you for this, but we prefer to keep it as bunx and not bun x

[colinhacks]

Seems symlinking fails in codespaces, might be useful for reproduction: microsoft/playwright#26454 (comment)