The WindowServer _really_ does not need to know the filesystem path to
it's wallpaper, and allows setting arbitrary wallpapers (those outside
of `/res/wallpapers`).
The GUI::Desktop will keep track of the path to the wallpaper (if any),
and save it to config if desired (to be persisted).
This avoids the need to `unveil` paths to the wallpaper, fixing #11158
SPDX License Identifiers are a more compact / standardized
way of representing file license information.
See: https://spdx.dev/resources/use/#identifiers
This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
