Use context manager to avoid permission error on Windows

[jgerityneurala]

Pull Request Description:

The Model Compression Toolkit appears to have a bug on Windows caused by trying to remove a file that is still open. Linux allows for deleting a file that is still open, but Windows is much more particular about this operation and in general trying to remove a file that is still open somewhere will result in a PermissionError. Here's a standalone reproduction of the fundamental problem:

PS C:\Users\James> py -3.9
Python 3.9.9 (tags/v3.9.9:ccb0e6a, Nov 15 2021, 18:08:50) [MSC v.1929 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import os, tempfile
>>> handle, tmpfile = tempfile.mkstemp()
>>> os.remove(tmpfile)  # File handle is still open, Windows will refuse to remove the file
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
PermissionError: [WinError 32] The process cannot access the file because it is being used by another process: 'C:\\Users\\James\\AppData\\Local\\Temp\\tmp8m6l666s'  
>>> os.close(handle)
>>> os.remove(tmpfile)  # If the file is first closed, it can be safely removed

I can confirm that changing the affected code inside of MCT to os.close() the handle before calling os.remove() does resolve the problem, but I have written this PR to use tempfile.NamedTemporaryFile as a context manager, which handles close/removal of the file automatically, and will also clean up the file if an error occurs during export.

Checklist before requesting a review:

• I set the appropriate labels on the pull request.
• [N/A] I have added/updated the release note draft (if necessary).
• [N/A] I have updated the documentation to reflect my changes (if necessary).
• [N/A] All function and files are well documented.
• [N/A] All function and classes have type hints.
• There is a licenses in all file.
• The function and variable names are informative.
• I have checked for code duplications.
• [N/A] I have added new unittest (if necessary).

[reuvenperetz]

Hello @jgerityneurala,
Thanks for your contribution! :)