Uninstall PIO Core and dependent packages

• The isolated installation of PIO Core and dependent packages are installed to the core_dir folder. Just remove it.

• Uninstall global PIO Core if you did not use the Installer Script (Recommended):

  # uninstall standalone PIO Core installed via `pip`
  pip uninstall platformio
  
  # uninstall Homebrew's PIO Core (only macOS users if you installed it via Homebrew before)
  brew uninstall platformio