Add missing apt-get update before apt-get install

Author: byroot

.github/workflows/test.yml

@@ -42,6 +42,7 @@ jobs:
 
       - name: Test run_benchmarks.rb --graph
         run: |
+          sudo apt-get update
           sudo apt-get install -y --no-install-recommends libmagickwand-dev
           ./run_benchmarks.rb --graph fib
         if: matrix.ruby == 'ruby'