disable pyav==9.1.1 on windows

Author: pmeier

.circleci/unittest/windows/scripts/environment.yml

@@ -14,6 +14,6 @@ dependencies:
     - future
     - pillow >=5.3.0, !=8.3.*
     - scipy
-    - av
+    - av != 9.1.1
     - dataclasses
     - h5py