Log Message:
editors/featherpad: update to 1.3.1

D-Bus is used — instead of the old, network-based method — for making the app
have a single process. D-Bus is faster, more versatile, and much more reliable,
especially under extreme circumstances.

FeatherPad still works under non-Linux systems without D-Bus, but as a
multi-process app.

Other changes:

● The qmake compilation has been removed. Its maintenance wasn't justified,
  especially with D-Bus.
● A workaround has been added for a Qt5 bug that caused a crash if SIGTERM was
  sent while the replacement dock was visible. The bug doesn't exist in Qt6.