Fix typo in CI.yml

Author: juliohm

.github/workflows/CI.yml

@@ -52,5 +52,5 @@ jobs:
       - uses: julia-actions/julia-processcoverage@v1
       - uses: codecov/codecov-action@v5
         with:
-          file: lcov.info
+          files: lcov.info
           token: ${{ secrets.CODECOV_TOKEN }}