I intend to orphan the singleapplication package due to unsolvable
bug https://bugs.debian.org/1050520 , incompatibility with Qt6.6+,
and upstream moving to a non-free license.

The package description is:
 Project SingleApplication is a replacement of QtSingleApplication
 for Qt5. It helps to keep the primary instance of your application
 and kill each subsequent instances. If enabled, it can also spawn
 secondary (non-related to the primary) instances and send data to
 the primary instance from secondary instances.

Thanks,
Boyuan Yang