Add MODTK_BIN to SUBST_VARS; no longer added by the Tk port module.



diff -Nurp /usr/ports//graphics/gocr/Makefile ./Makefile
--- /usr/ports//graphics/gocr/Makefile	Thu Oct  5 10:49:27 2023
+++ ./Makefile	Sat Feb  7 10:11:16 2026
@@ -23,6 +23,7 @@ CONFIGURE_STYLE=gnu
 CONFIGURE_ARGS=	--with-netpbm=${PREFIX}
 USE_GMAKE=	Yes
 FAKE_FLAGS+=	prefix=${PREFIX} exec_prefix=${PREFIX}
+SUBST_VARS=	MODTK_BIN
 
 MULTI_PACKAGES=	-main -gui