Update Ubuntu version for CI

Author: janheinrichmerker

.github/workflows/release.yml

@@ -8,7 +8,7 @@ on:
 jobs:
   build:
     name: "🚀 Release"
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-latest
     steps:
       - name: "📥 Check-out"
         uses: actions/checkout@v1