[vscode-lldb] Fix `yarn package` (#152002)

# Problem
`yarn package` cannot be run twice in a row - the second time will error
out:
> Error: ENOENT: no such file or directory, stat
'<path>/llvm-project/lldb/tools/lldb-dap/out/lldb-dap.vsix'

This error is also weird, because the file actually exists. See the end
of this [full
output](https://gist.github.com/royitaqi/f3f4838ed30d7ade846f53f0fb7d68f4).

# Fix

Delete the `lldb-dap.vsix` file at the start of each run. See
consecutive runs [being
successful](https://gist.github.com/royitaqi/9609181b4fe6a8a4e71880c36cd0c7c9).

GitOrigin-RevId: 4882874ddc1017f2f1b9b11fb67065440b101701
1 file changed