Add hidden import to PyInstaller build (GH-2466)

Add new platformdirs dependencies as hidden imports when creating
PyInstaller-based binaries.

platformdirs imports the module for each platform dynamically, which
PyInstaller is unable to correctly detect for packing. By adding the
modules as hidden imports, we are telling PyInstaller to include the
modules in the packaged binary.

This issue seems to have been introduce when switching to platformdirs
in #2375. fixes #2464

Commit history before merge:

* Add hidden import to PyInstaller build

Add new platformdirs dependency as a hidden import when creating
PyInstaller based binaries.

* Only include the platformdirs for the relevant os