Decrease the Live ISO size

[lslezak]

Problem

• After switching to Wayland and Gnome kiosk the Live ISO size increased significantly

Solution

• Delete some not needed packages or individual big files
• Unfortunately most of them are pulled in by some dependencies so they need to be deleted by force (ignoring dependencies)
• It turned out that using the patternType="onlyRequired" option in the Kiwi file as suggested here does not change anything. (Probably it applies only to patterns, but we install Wayland and Gnome kiosk as individual packages, we do not use a pattern for that. Or it is enabled by default...)

Result

• The image size decreased from 693MB to 662MB, saving about 31MB (-4.5%).
• We can apply only a subset of the proposal if we consider some removal is dangerous.
• Saved size for each individual part:
  • python: -11MB
  • libyui-ncurses: -1MB
  • iso-codes: -2MB
  • gtk4-tools: -2MB
  • gnome-control-center: -2MB
  • gnome-themes-accessibility: -2MB
  • gweather4-data: -1MB
  • codecs: -6MB
  • gstreamer: -3MB
  • jsonnet-lint: -3MB
  • Firefox crashreporter: -2MB

Notes

• Due to rounding the sum of the saved parts do not exactly match the total saved space, the numbers are only approximate.
• The numbers are for the x86_64 architecture, on the other architectures the numbers will be very likely different. The ppc64le and s390x images are already much smaller so the size decrease will be smaller as well.

Testing

• Tested manually, the built Live ISO still boots 😃

[DimStar77]

The dep chain leading to gnome-control-center is:

• rpm -qgdm-systemd -> gnome-shell -> gnome-control-center
  The dep generally does make sense, as gnome-shell does integrate the control-center directly into the panel (it's absence should not cause a problem; for TW, we might move that dep to the pattern and remove it from gnome-shell)

the dep chain leading to gweather4-data is:

• gweather4-data is a dependency (brings glib schema and location database) for libgweather, linked into gnome-settings-daemon; settings-daemon is needed by mutter and gnome-session;

dep chain leading to python313-base:

• /usr/bin/python3 is needed by hyper-v, xfsprogs, and bache-tools

some other potential candidates:

nodejs22

• nodejs22 is 6MB in size and is only pulled in as a dependency to agama-integration-tests; Is that really needed on the actual live image?

epiphany vs Firefox?

• It might be worthy to check if Firefox (~270MB) could be replaced with GNOME Web (aka epiphany, ~ 135MB)