IMPORTANT: This will force-enable this option in user preferences, as part of the 5.0 versioning process. Users that do want to keep saving uncompressed blendfiles will have to edit their user preferences accordingly, and re-save them. This commit does _not_ change the setting for an existing blendfile: uncompressed blendfiles will keep being saved as uncompressed. Implements #135735. Pull Request: https://projects.blender.org/blender/blender/pulls/146172