Fix codecov

Author: cffls

.github/workflows/main.yml

@@ -33,9 +33,10 @@ jobs:
           poetry run pytest --doctest-modules --ignore=examples --cov=pycardano --cov-config=.coveragerc --cov-report=xml
       - name: "Upload coverage to Codecov"
         if: ${{ matrix.python-version == '3.11' }}
-        uses: codecov/codecov-action@v3
+        uses: codecov/codecov-action@v4
         with:
           fail_ci_if_error: true
+          token: ${{ secrets.CODECOV_TOKEN }}
       - name: Run static analyses
         run: |
           make qa