www/waterfox: Update 6.5.9 => 6.6.0-beta-2

Changes:
Platform Changes (128.0 to 140.0)
https://www.waterfox.net/docs/releases/6.6.0-beta-1/
https://www.waterfox.net/docs/releases/6.6.0-beta-2/

Improve port:

• Fix build on i386 - use www/node24 on i386 and hande sse2.
• Unification of Makefile with Firefox - make it more similar.
• Use ${DESKTOPDIR} instead if ${PREFIX}/share/applications.

PR: 288283 288109
MFH: 2025Q3