Remove default membership in redundant groups (canonical#4258)

The cloud-init template for Ubuntu currently includes membership in
numerous groups. Many of these are groups that were removed from the
default list over a decade ago on the desktop, and which are better
served by udev rules today. Specifically: audio, dialout, floppy,
netdev, plugdev, video.

LP: #1923363

config/cloud.cfg.tmpl

@@ -206,7 +206,7 @@ system_info:
      name: ubuntu
      lock_passwd: True
      gecos: Ubuntu
-     groups: [adm, audio, cdrom, dialout, dip, floppy, lxd, netdev, plugdev, sudo, video]
+     groups: [adm, cdrom, dip, lxd, sudo]
      sudo: ["ALL=(ALL) NOPASSWD:ALL"]
      shell: /bin/bash
 {# SRU_BLOCKER: do not ship network renderers on Xenial, Bionic or Eoan #}

doc/examples/cloud-config-user-groups.txt

@@ -146,4 +146,4 @@ users:
 #     shell: /bin/bash
 #     lock_passwd: True
 #     gecos: Ubuntu
-#     groups: [adm, audio, cdrom, dialout, floppy, video, plugdev, dip, netdev]
+#     groups: [adm, cdrom, dip, lxd, sudo]

doc/rtd/reference/base_config_reference.rst

@@ -348,7 +348,7 @@ On an Ubuntu system, :file:`/etc/cloud/cloud.cfg` should look similar to:
         name: ubuntu
         lock_passwd: True
         gecos: Ubuntu
-        groups: [adm, audio, cdrom, dialout, dip, floppy, lxd, netdev, plugdev, sudo, video]
+        groups: [adm, cdrom, dip, lxd, sudo]
         sudo: ["ALL=(ALL) NOPASSWD:ALL"]
         shell: /bin/bash
       network:

tools/.github-cla-signers

@@ -153,6 +153,7 @@ tylerschultz
 vorlonofportland
 vteratipally
 Vultaire
+waveform80
 WebSpider
 Wind-net
 wmousa