The heaptrack traces reported in the trace points towards those lines causing leaking: http://45.86.162.4/files/2022/heaptrack.dolphin.1944565_19.zst
I don't understand where the leak occurs but there seem to be one in the Solid::Backends::UDisks2::Device::Device() ctor.
This change should help even-though it does not prevent the leak, it will make it less occurring.