Merge pull request #580 from pytroll/dependabot/github_actions/codecov/codecov-action-4

Bump codecov/codecov-action from 3 to 4

Author: djhoese

.github/workflows/ci.yaml

@@ -80,7 +80,7 @@ jobs:
           cd docs && mkdir doctest && sphinx-build -E -n -b doctest ./source ./doctest && cd ..
 
       - name: Upload unittest coverage to Codecov
-        uses: codecov/codecov-action@v3
+        uses: codecov/codecov-action@v4
         with:
           flags: unittests
           file: ./coverage.xml