Enforce Windows 10 requirement for NVDA (#18688)
Closes #18684
Summary of the issue:
NVDA 2025.3 and earlier requires Windows 8.1. With 2026.1 and with Python 3.13 dropping active support for Windows 8.1, NVDA will now require Windows 10 (1507) or later.
Description of user facing changes:
Notable changes include:
System requirement set to Widows 10 (in code and in user-facing documentation)
Windows OneCore will be used as default speech synthesizer.
Description of developer facing changes:
The following changes were made:
SConscript: Windows subsystem set to Windows 10
winVersion: removed recognition of Windows 8.1 (the constant itself is deprecated) and minimum version set to Windows 10
Removed winVersion.WIN10 checks from the source code, including speech synthesizer list (OneCore is used by default)
Description of development approach:
Edited the NVDA source code to remove checks on winVersion.WIN10, similar to the approach taken in #15544 and friends.
