sysext: turn vim to a sysext image

[tormath1]

In this PR, we propose to turn vim to a sysext image built without minimal compiling option. The sysext will be enabled by default to not break existing Vim usage.

• Folks interested to have vim on Flatcar will enjoy the full experience
• Folks not interested to have vim on Flatcar (and its regular amount of CVEs) will be able to remove it

One could drop Vim from Flatcar with the current configuration:

variant: flatcar
version: 1.1.0
storage:
  files:
    - path: /etc/flatcar/enabled-sysext.conf
      overwrite: true
      contents:
        inline: |
          -vim

How to use

Use vim as usual:

core@localhost ~ $ systemd-sysext status
HIERARCHY EXTENSIONS         SINCE
/opt      none               -
/usr      containerd-flatcar Tue 2024-12-03 14:33:23 UTC
          docker-flatcar
          flatcar-vim
          oem-qemu

• Changelog entries added in the respective changelog/ directory (user-facing change, bug fix, security fix, update)
• Inspected CI output for image differences: /boot and /usr size, packages, list files for any missing binaries, kernel modules, config files, kernel modules, etc.
• CI: http://localhost:8080/job/container/job/packages_all_arches/5056/cldsv/

Note / TODO:

• This currently needs to be reworked (for some reasons Vim is still in the generic image)
• We might need to rework the way we enable / disable sysexts images (e.g using /etc/flatcar/sysexts.d/ drop-ins files)
• Need to check the size of the new generic image with the "huge" vim:

$ du --si flatcar-vim.raw
5.7M	flatcar-vim.raw

Related to:

• vim as a built-in sysext image and remove it from the base image Flatcar#1463
• Add a sysext for vim-huge sysext-bakery#78