ci: remove codecov token

Author: deandreamatias

.github/workflows/base.yaml

@@ -51,8 +51,6 @@ jobs:
         run: dart pub publish --dry-run
       - name: Upload coverage to Codecov
         uses: codecov/codecov-action@v5
-        env:
-          CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
         with:
           files: coverage/lcov.info
           flags: unittests