Update
So I imaged the 64bit version of Raspian buster to a SD card with Balena and booted up my Pi4
This did not change anything since 2.3.0 remains the latest release supported by the maintainer. Same messages about missing requirements. Digging a bit more thoroughly in the download page there is some comment toward the bottom suggesting that only by building from the 64 bit _source_ is it possible to bypass the installation problems with WSJTX version 2.5.4. Some inclusions in the 2.5.4 package are not supported by their maintainers if I understand it correctly. Think Hamlib perhaps.
So the latest version that can be installed on the Pi without building from source remains 2.3.0.
Commenter Jerry got this correct it seems. I looked at building from source but this is non trivial in my estimation.
I also looked at Ham Pi but it is not clear to me that WSJTX 2.5.4 is included. It seems he is experimenting with the 64 bit versions.
I also tried "sudo apt-get --fix-broken install" but this did not find any problem to fix. I probably did something in error.
For now, I am staying with version 2.3.0 until these dependencies are resolved by the package maintainers. There is plenty to explore in the K4 to keep me busy<smile>.
*** Ben KE3KQ
KE3KQ