Fixup: use 20.21.1 instead

Author: hmstepanek

.github/actions/setup-python-matrix/action.yml

@@ -47,4 +47,4 @@ runs:
       shell: bash
       run: |
         python3.10 -m pip install -U pip
-        python3.10 -m pip install -U wheel setuptools 'tox<4' 'virtualenv<20.21.1'
+        python3.10 -m pip install -U wheel setuptools 'tox<4' 'virtualenv<20.22.0'