chore(deps): update actions/download-artifact action to v4.2.1

Author: renovate[bot]

.github/workflows/ruby.yml

@@ -136,7 +136,7 @@ jobs:
       - name: Give test coverage reporter executable permissions
         run: chmod +x cc-test-reporter
 
-      - uses: actions/download-artifact@v4.1.8
+      - uses: actions/download-artifact@v4.2.1
         with:
           name: coverage-${{ matrix.ruby }}
           path: coverage