Update codecov token name to match other repos

Author: natemort

.github/workflows/codecov.yml

@@ -13,5 +13,5 @@ jobs:
       - name: Upload coverage to Codecov
         uses: codecov/codecov-action@v4
         env:
-          CODECOV_TOKEN: ${{ secrets.CODECOV_ORG_TOKEN }}
+          CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
           slug: uber/cadence