update ubuntu image in GH actions script

Author: ericniebler

.github/workflows/gh-pages.yml

@@ -7,7 +7,7 @@ on:
 
 jobs:
   build-and-publish:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-22.04
     steps:
       - uses: actions/checkout@v2
       - run: sudo apt-get install make