graphics/plantuml: Update 1.2025.10 => 1.2026.1
Changelogs:
https://github.com/plantuml/plantuml/releases/tag/v1.2026.0
https://github.com/plantuml/plantuml/releases/tag/v1.2026.1
PR: 292606
Approved by: awoonya <awoonyaa@gmail.com> (maintainer, implicit - innactive almost 2 years)