Upgrade pywin32 version constraint in setup.py

Updated the pywin32 version constraint to match the newer version
specified in the project requirements.txt.

Signed-off-by: dorranh <dorran.howell@tweag.io>

setup.py

@@ -16,7 +16,7 @@
 
 extras_require = {
     # win32 APIs if on Windows (required for npipe support)
-    ':sys_platform == "win32"': 'pywin32==227',
+    ':sys_platform == "win32"': 'pywin32==301',
 
     # If using docker-py over TLS, highly recommend this option is
     # pip-installed or pinned.