install: Resupport Ubuntu 22.04.

Signed-off-by: Anders Kaseorg <anders@zulip.com>

.github/workflows/production-suite.yml

@@ -106,13 +106,17 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
+        extra_args: [""]
         include:
           # Docker images are built from 'tools/ci/Dockerfile'; the comments at
           # the top explain how to build and upload these images.
           - docker_image: zulip/ci:focal
             name: Ubuntu 20.04 production install
             os: focal
-            extra_args: ""
+
+          - docker_image: zulip/ci:jammy
+            name: Ubuntu 22.04 production install
+            os: jammy
 
           - docker_image: zulip/ci:bullseye
             name: Debian 11 production install with custom db name and user

.github/workflows/zulip-ci.yml

@@ -15,6 +15,8 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
+        include_documentation_tests: [false]
+        include_frontend_tests: [false]
         include:
           # Base images are built using `tools/ci/Dockerfile.prod.template`.
           # The comments at the top explain how to build and upload these images.
@@ -23,13 +25,15 @@ jobs:
             name: Ubuntu 20.04 (Python 3.8, backend + frontend)
             os: focal
             include_frontend_tests: true
-            include_documentation_tests: false
           # Debian 11 ships with Python 3.9.2.
           - docker_image: zulip/ci:bullseye
             name: Debian 11 (Python 3.9, backend + documentation)
             os: bullseye
             include_documentation_tests: true
-            include_frontend_tests: false
+          # Ubuntu 22.04 ships with Python 3.10.4.
+          - docker_image: zulip/ci:jammy
+            name: Ubuntu 22.04 (Python 3.10, backend)
+            os: jammy
 
     runs-on: ubuntu-latest
     name: ${{ matrix.name }}