file -> files in codecov ci (#350)

Author: blegat

.github/workflows/ci.yml

@@ -38,7 +38,7 @@ jobs:
         env:
           DATADEPS_ALWAYS_ACCEPT: true # For MLDatasets.MNIST
       - uses: julia-actions/julia-processcoverage@v1
-      - uses: codecov/codecov-action@v4
+      - uses: codecov/codecov-action@v5
         with:
-          file: lcov.info
+          files: lcov.info
           token: ${{ secrets.CODECOV_TOKEN }}