Upgrade development environment to Ubuntu 22.04.

Signed-off-by: Anders Kaseorg <andersk@mit.edu>

Vagrantfile

@@ -15,7 +15,7 @@ Vagrant.configure("2") do |config|
   ubuntu_mirror = ""
   vboxadd_version = nil
 
-  config.vm.box = "bento/ubuntu-20.04"
+  config.vm.box = "bento/ubuntu-22.04"
 
   config.vm.synced_folder ".", "/vagrant", disabled: true
   config.vm.synced_folder ".", "/srv/zulip", docker_consistency: "z"

docs/development/setup/vagrant-ssh.md

@@ -8,7 +8,7 @@ $ vagrant ssh
 You should see output that starts like this:
 
 ```console
-Welcome to Ubuntu 20.04.4 LTS (GNU/Linux 5.4.0-107-generic x86_64)
+Welcome to Ubuntu 22.04.3 LTS (GNU/Linux 5.15.0-92-generic x86_64)
 ```
 
 Congrats, you're now inside the Zulip development environment!

docs/development/setup/vagrant-up.md

@@ -1,7 +1,7 @@
 The first time you run this command it will take some time because Vagrant
 does the following:
 
-- downloads the base Ubuntu 20.04 virtual machine/Docker image
+- downloads the base Ubuntu 22.04 virtual machine/Docker image
 - configures this virtual machine/container for use with Zulip,
 - creates a shared directory mapping your clone of the Zulip code inside the
   virtual machine/container at `~/zulip`

tools/droplets/README.md

@@ -130,7 +130,7 @@ so they are notified.
    - Check "Monitoring", "IPv6", and "User data"
    - Paste the contents of `tools/droplets/new-droplet-image` into the
      text box which says `Enter user data here...`
-   - Name it e.g. `base-ubuntu-20-04.zulipdev.org`
+   - Name it e.g. `base-ubuntu-22-04.zulipdev.org`
 1. Add an A record for `base.zulipdev.org` to point to the new host.
 1. Wait for the host to boot.
 1. `scp tools/droplets/new-droplet-image base.zulipdev.org:/tmp/new-droplet-image`

tools/setup/dev-vagrant-docker/Dockerfile

@@ -1,4 +1,4 @@
-FROM ubuntu:20.04
+FROM ubuntu:22.04
 
 ARG UBUNTU_MIRROR
 

tools/setup/vagrant-provision

@@ -12,8 +12,8 @@ set -o pipefail
 
 # Set the MOTD on the system to have Zulip instructions
 sudo ln -nsf /srv/zulip/tools/setup/dev-motd /etc/update-motd.d/99-zulip-dev
-sudo rm -f /etc/update-motd.d/10-help-text
-sudo dpkg --purge landscape-client landscape-common ubuntu-release-upgrader-core update-manager-core update-notifier-common ubuntu-server
+sudo rm -f /etc/update-motd.d/10-help-text /etc/update-motd.d/99-bento
+sudo dpkg --purge landscape-common
 sudo dpkg-divert --add --rename /etc/default/motd-news
 sudo sh -c 'echo ENABLED=0 > /etc/default/motd-news'