Bump runner image to ubuntu-22.04

Author: Philippus

.github/workflows/build.yml

@@ -2,7 +2,7 @@ name: Build
 on: [push, pull_request]
 jobs:
   build:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     steps:
       - uses: actions/checkout@v4
       - name: Set up Ruby