Remove references to 32-bit Windows from the user guide

[SaschaCowley]

Link to issue number:

Closes #19222

Summary of the issue:

The user guide makes references to running NVDA on 32-bit Windows.

Description of user facing changes:

The user guide no longer makes such references.

Description of developer facing changes:

None

Description of development approach:

Searched the user guide for 32 and 86. Updated contents as appropriate.

Installed MSSP x64 and ensured that it works with 64-bit NVDA.

Testing strategy:

Build user guide, check for obvious errors.

Known issues with pull request:

None

Code Review Checklist:

• Documentation:
  • Change log entry
  • User Documentation
  • Developer / Technical Documentation
  • Context sensitive help for GUI changes
• Testing:
  • Unit tests
  • System (end to end) tests
  • Manual testing
• UX of all users considered:
  • Speech
  • Braille
  • Low Vision
  • Different web browsers
  • Localization in other languages / culture than English
• API is compatible with existing add-ons.
• Security precautions taken.

[Qchristensen]

Looks good.