Update Ubuntu for CI

Author: cowtowncoder

.github/workflows/main.yml

@@ -11,12 +11,11 @@ on:
     - master
 jobs:
   build:
-    runs-on: ${{ matrix.os }}
+    runs-on: 'ubuntu-22.04'
     strategy:
       fail-fast: false
       matrix:
         java_version: ['8', '11', '17']
-        os: ['ubuntu-20.04']
     env:
       JAVA_OPTS: "-XX:+TieredCompilation -XX:TieredStopAtLevel=1"
     steps: