Add pywin32 to catapult's root .vpython spec.
Add pywin32 to catapult's root .vpython spec.

Some recent recipe engine and/or depot_tools change are causing
python import errors on windows when running telemetry's glcient hook:
https://chromium-swarm.appspot.com/task?id=4bc54c199bbf9410

This may fix that.

Bug: chromium:1074405
Change-Id: I8001dbc00afcd27ca1fa284da625852785f638af
Reviewed-on: https://chromium-review.googlesource.com/c/catapult/+/2165632
Reviewed-by: Brian Sheedy <8cdc5cc1fa60ba15acb0d296e6f5592b7bb7d71c@chromium.org>
Commit-Queue: Ben Pastene <e214258550f76fa23ac7c1d953424f3f468f5c6b@chromium.org>

catapult-project/catapult,catapult-project/catapult,catapult-project/catapult,catapult-project/catapult,catapult-project/catapult,catapult-project/catapult,catapult-project/catapult