graphics/plutovg: Update 1.3.1 => 1.3.2

Changelogs:

• https://github.com/sammycage/plutovg/releases/tag/v1.3.2
• https://github.com/sammycage/plutovg/compare/v1.3.1...v1.3.2

Approved by: db@, yuri@ (Mentors, implicit)
Differential Revision: https://reviews.freebsd.org/D54278