Fixes broken codecov in CI

The codecov github action we use in CI is now v4, which requires CODECOV_TOKEN to function. This makes it so that CI action uses the CODECOV_TOKEN secret.

Author: brews

.github/workflows/pythonpackage.yaml

@@ -66,4 +66,6 @@ jobs:
         run: |
           pytest -v --cov dscim --cov-report term-missing --cov-report xml
       - name: Upload coverage to Codecov
-        uses: codecov/codecov-action@v4
+        uses: codecov/codecov-action@v4
+        env:
+          CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}