Reported by @woeful crag
Bug Report: Copying code also copies line number
`Steps to Reproduce`
Remove the line number when generating a code output.
`Expected Result`
When user clicks the "Copy code" button in a code response, the line number should not be copied.
`Actual Result`
When user clicks the "Copy code" button in a code response, the line number is also copied and is shown when pasted.
`Environment`
MacOS 15, Google Chrone