Blender: change bugfix release versioning from a/b/c to .1/.2/.3

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

release/scripts/startup/bl_operators/wm.py

@@ -1106,8 +1106,8 @@ class WM_OT_doc_view(Operator):
 
     doc_id: doc_id
     if bpy.app.version_cycle in {"release", "rc", "beta"}:
-        _prefix = ("https://docs.blender.org/api/%d.%d%s" %
-                   (bpy.app.version[0], bpy.app.version[1], bpy.app.version_char))
+        _prefix = ("https://docs.blender.org/api/%d.%d" %
+                   (bpy.app.version[0], bpy.app.version[1]))
     else:
         _prefix = ("https://docs.blender.org/api/master")