I mistakenly thought that Steam Linux Runtime 3.0 was new in SteamOS 3.5 when I initially wrote this. As it turns out, it's been around since 2021 and is the wrapper used in Proton 8. If there are issues with this runtime we can roll it back, but I don't expect there will be any.
Also updated to use KDialog boxes for errors with the wrapper script so that it doesn't have to be run from a terminal to find out if the runtimes are not where we expect them to be.
I mistakenly thought that Steam Linux Runtime 3.0 was new in SteamOS 3.5 when I initially wrote this. As it turns out, it's been around since 2021 and is the wrapper used in Proton 8. If there are issues with this runtime we can roll it back, but I don't expect there will be any.
Also updated to use KDialog boxes for errors with the wrapper script so that it doesn't have to be run from a terminal to find out if the runtimes are not where we expect them to be.