Fix Anaconda environment configuration for tests

In order to fix scitt-community#38, we need to hard
pin the version of Werkzeug used by Flask to avoid the changes after
to how functions are organized in the library's modules.

See PR Sanster/IOPaint#390 with a related solution (not specific to
Anaconda approach, but informative).

See [StackOverflow](https://stackoverflow.com/a/77217971) post for
details.

environment.yml

@@ -41,3 +41,4 @@ dependencies:
     - cwt==2.7.1
     - py-multibase==1.0.3
     - py-multicodec==0.2.1
+    - werkzeug==2.2.2