The file subversion is no longer used in the Python API or user interface,
and is now internal to Blender.
User interface, Python API and file I/O metadata now use more consistent
formatting for version numbers. Official releases use "2.83.0", "2.83.1",
and releases under development use "2.90.0 Alpha", "2.90.0 Beta".
Some Python add-ons may need to lower the Blender version in bl_info to
(2, 83, 0) or (2, 90, 0) if they used a subversion number higher than 0.
https://wiki.blender.org/wiki/Reference/Release_Notes/2.83/Python_API#Compatibility
This change is in preparation of LTS releases, and also brings us more
in line with semantic versioning.
Fixes T76058.
Differential Revision: https://developer.blender.org/D7748
