'two-browser' tag separates out tests that run multiple browsers in pipeline so that --parallel tests don't interfere w. loading of one or more of such windows; both FTs.test_sharing & woodpecker.yaml updated accordingly

.woodpecker.yaml

@@ -37,7 +37,8 @@ steps:
       - pip install -r requirements.txt
       - cd ./src
       - python manage.py collectstatic --noinput
-      - python manage.py test functional_tests --parallel --exclude-tag=channels
+      - python manage.py test functional_tests --parallel --exclude-tag=channels --exclude-tag=two-browser
+      - python manage.py test functional_tests --tag=two-browser
       - python manage.py test functional_tests --tag=channels
     when:
       - event: push