Remove old web_terminal_spec

What does this MR do and why?

Describe in detail what your merge request does and why.

Removes old browser_ui/3_create/web_ide/web_terminal_spec.rb E2E that has been in quarantine for more than a year due to a long-standing bug that is unlikely to be fixed now that we are moving to a new Web IDE. Also, this feature is not available in the new Web IDE Beta, we can look into creating a new test if it is added in the future.

For more information see #338179 (closed)

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.