Update unittests.yml

bump codecov action

Author: knaaptime

.github/workflows/unittests.yml

@@ -78,7 +78,7 @@
            --cov-report xml
 
        - name: codecov
-         uses: codecov/codecov-action@v3
+         uses: codecov/codecov-action@v5
          with:
            token: ${{ secrets.CODECOV_TOKEN }}
            file: ./coverage.xml