Bump GiHub actions runner (#782)

Author: unsortedhashsets

.github/workflows/main.yml

@@ -4,7 +4,7 @@ on: [ push ]
 jobs:
   build:
     name: Build and push image
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
 
     steps:
     - uses: actions/checkout@v2