QOperatingSystemVersion: Adding new const entries in patch releases breaks our BC guarantees

Each static const entry emits a new symbol. This goes against our BC guarantees for patch versions where we promise that users can freely downgrade the Qt libraries without any recompilation as long as it's inside the same minor version.

This means we can only effectively add new static const entries to QOperatingSystemVersion in minor releases.

For Qt 7 the class should be redesigned so that it can have all the entries be inline, and not have them emit symbols.