Update Codecov action to version 4

Author: pulsipher

.github/workflows/CI.yml

@@ -27,6 +27,8 @@ jobs:
           arch: ${{ matrix.arch }}
       - uses: julia-actions/julia-runtest@latest
       - uses: julia-actions/julia-processcoverage@v1
-      - uses: codecov/codecov-action@v3
+      - uses: codecov/codecov-action@v4
+        env:
+          CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
         with:
-          file: lcov.info
+          file: lcov.info