Upgrade CI workflow to use Ubuntu 22.04

Author: BenjiU

.github/workflows/ci.yml

@@ -30,7 +30,7 @@ jobs:
   publish:
     name: Publish to PyPI
     if: github.event_name == 'release' && github.event.action == 'created'
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     needs: test
     steps:
       - uses: actions/checkout@v2
@@ -50,7 +50,7 @@ jobs:
   build_docker_image:
     name: Build Docker Image
     if: (github.event_name == 'release' && github.event.action == 'created') || github.event_name == 'push'
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     needs: test
     steps:
       - uses: actions/checkout@v2
@@ -80,7 +80,7 @@ jobs:
     name: Generate Documentation
     if: github.event_name == 'push'
     concurrency: generate_docs
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     steps:
       - uses: actions/checkout@v2
         with: