Replace deprecated pipes module with shlex.quote

[sterliakov]

pipes.quote is undocumented. It is mentioned in 2.7 docs as deprecated and exported as shlex.quote. Now whole pipes module is deprecated as of 3.11 and scheduled for removal in python 3.13.

Currently using executor results in a deprecation warning:

../../.venv/lib/python3.11/site-packages/executor/__init__.py:47
  /.venv/lib/python3.11/site-packages/executor/__init__.py:47: DeprecationWarning: 'pipes' is deprecated and slated for removal in Python 3.13
    import pipes

[elementalvoid]

@sterliakov 👋. Sorry, I looked for a fix for this a couple of weeks ago and your PR didn't exist yet. When I implemented #22 today I didn't check in again before doing so!

I'm not sure if @xolox has any desire to maintain 2.7 compatibility but that's the main difference between our two PRs.