Update ci.yml for codecov

Author: joaquimg

.github/workflows/ci.yml

@@ -40,3 +40,6 @@ jobs:
       - uses: julia-actions/julia-runtest@v1
       - uses: julia-actions/julia-processcoverage@v1
       - uses: codecov/codecov-action@v5
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
+          slug: LAMPSPUC/ApplicationDrivenLearning.jl