The Cura 4.9 release will have expanded functionality. If you have a plug-in that uses this functionality, marking it as using SDK 7.5.0 will notify older Cura releases that they can't use that plug-in.
We're changing the unit of one of our settings, so we need to implement a version upgrade to change that for our users in case they changed this setting themselves.
Contributes to issue CURA-7118.
