more action updates

Author: bmcfee

.github/workflows/ci.yml

@@ -50,7 +50,7 @@ jobs:
         python -m pytest tests
         python -m pytest --doctest-only resampy
     - name: Upload coverage to Codecov
-      uses: codecov/codecov-action@v3
+      uses: codecov/codecov-action@v4
       with:
         token: ${{ secrets.CODECOV_TOKEN }}
         files: ./coverage.xml