chore(deps): update codecov/codecov-action action to v4 (#10)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/test.yml

@@ -103,6 +103,6 @@ jobs:
       - name: cargo llvm-cov
         run: cargo llvm-cov --locked --all-features --lcov --output-path lcov.info
       - name: Upload to codecov.io
-        uses: codecov/codecov-action@v3
+        uses: codecov/codecov-action@v4
         with:
           fail_ci_if_error: true