🐛🔧 Use tox3 for tests @ GHA under Windows

Tox4 does not work correctly in our CI under Windows. Limiting the
version is a workaround to be used until it's fixed.

Ref: tox-dev/tox#2692

Author: webknjaz

.github/workflows/ci-cd.yml

@@ -609,11 +609,14 @@ jobs:
           }}-
           ${{ runner.os }}-pip-
     - name: Install tox
+      # NOTE: Tox4 does not work correctly in our CI under Windows. Limiting the
+      # NOTE: version is a workaround to be used until it's fixed.
+      # Ref: https://github.com/tox-dev/tox/issues/2692
       run: >-
         python -m
         pip install
         --user
-        tox
+        "tox${{ runner.os == 'Windows' && ' < 4' || '' }}"
 
     - name: Download all the dists
       uses: actions/download-artifact@v3