Fix Skim viewer crash by casting script_file (PosixPath) → str

[alberti42]

Summary

Opening PDFs with the Skim viewer crashed with:

TypeError: expected string or bytes-like object
  at shlex.quote(...)
  at latextools/utils/external_command.py

Root cause: plugins/viewer/skim_viewer.py passed a pathlib.Path (script_file) in the command list to external_command(). That function later quotes each arg with shlex.quote(), which requires str/bytes.

Change

Cast script_file to str when building the command:

- command = ["/bin/sh", script_file, "-r"]
+ command = ["/bin/sh", str(script_file), "-r"]

[deathaxe]

Thanks!