Enabling this feature makes Xwayland send xtest events via
the remote desktop portal and libei.
XWayland will create a new session for each X client (it keeps
contexts around and reuses them if the cmdline matches, so not
every xdotool invocation produces a new portal prompt).
-listen <fd> option is deprecated in favor of the -listenfd option. This
change makes kwin query whether Xwayland supports the -listenfd option
at build time. If the pkg-config file is missing, we'll use the old listen
option.
The main advantage of SPDX license identifiers over the traditional
license headers is that it's more difficult to overlook inappropriate
licenses for kwin, for example GPL 3. We also don't have to copy a
lot of boilerplate text.
In order to create this change, I ran licensedigger -r -c from the
toplevel source directory.
