Make this run from source again on Windows.

cura/OAuth2/KeyringAttribute.py

@@ -15,7 +15,8 @@ if TYPE_CHECKING:
 import sys
 from UM.Platform import Platform
 if Platform.isWindows():
-    import win32timezone
+    if hasattr(sys, "frozen"):
+        import win32timezone
     from keyring.backends.Windows import WinVaultKeyring
     keyring.set_keyring(WinVaultKeyring())
 if Platform.isOSX():