So these are development runtimes, they can likely be removed.
About the app tootle, it is currently archived upstream. Meaning that, until development picks up again in upstream it will be stuck in the GNOME runtime version 42, this might be an issue when gnome apps start migrating to the 43 runtime.
You can also install it from apt with: apt install tootle the version in the deb repositories is not that different from the one on flathub.
maybe you can remove the flatpak version and install the apt version and then run again:
flatpak remove --unused
One of your flatpak applications from gnome ecosystem, com.bitstower.Markets has not yet updated to GNOME 42, which is why you have two runtimes of GNOME, one for 41 and another for 42:
GNOME Application Platform version 41 org.gnome.Platform 41 system
GNOME Application Platform version 42 org.gnome.Platform 42
Removing com.bitstower.Markets and running flatpak remove --unused would possibly save you about 743,5 MB of space or a bit more. Of course what apps you use is your personal preference, not mine.
And because you have some Qt/KDE applications, you also have the KDE runtimes, which takes about 700MB of space, plus the apps on top