Fix codecov/upload config

Author: PawelLipski

.circleci/config.yml

@@ -212,7 +212,8 @@ jobs:
       - run: pip3 install tox
       - run: tox -e coverage-combine
       - codecov/upload:
-          flags: "-f coverage.xml"
+          disable_search: true  # otherwise, requirements/coverage.txt gets picked up
+          files: coverage.xml
 
   "dry run releases":
     executor: ubuntu_executor