Remove the ui-requirement property on PurplePluginInfo
Review Request #1462 — Created May 20, 2022 and submitted
This never worked right, even before gplugin. To read the value we had to have
already opened the library, which means all of its symbols were resolved. So
all this really did was stop a plugin for loading under a different UI. As we
move towards separate config directories for each UI this problem goes away.
Ran and verified that plugins looked alright.