textproc/sigil: Update 2.4.2 => 2.5.0

Changelog:
https://github.com/Sigil-Ebook/Sigil/releases/tag/2.5.0

Improve port:

• replace LIB_DEPENDS=libGLX.so:graphics/libglvnd with USES=gl and USE_GL=opengl
• fix warning from poudriere - add USES=gl and USE_GL=opengl
• replace LDFLAGS+=-L${LOCALBASE}/lib with USES=localbase:ldconfig

PR: 287039