graphics/gpaint: Fix build with llvm16

- Pet portclippy

Approved by:	portmgr (blanket)
Sponsored by:	The FreeBSD Foundation

graphics/gpaint/Makefile

@@ -13,12 +13,20 @@ LICENSE_FILE=	${WRKSRC}/COPYING
 
 USES=		gnome libtool pkgconfig
 USE_GNOME=	gtk20 libglade2
+
 GNU_CONFIGURE=	yes
+
 LIBS+=		-lm
 
 PLIST_FILES=	${DATADIR}/glade/gpaint.glade \
 		bin/gpaint-2
 
+.include <bsd.port.options.mk>
+
+.if ${OPSYS} == FreeBSD && ( ${OSVERSION} >= 1400091 || ( ${OSVERSION} >= 1302507 && ${OSVERSION} < 1400000 ))
+CFLAGS+=	-Wno-error=incompatible-function-pointer-types
+.endif
+
 post-patch:
 	@${REINPLACE_CMD} -e \
 		's|_RESPONSE_DISCARD|_RESPONSE_NO|g' ${WRKSRC}/src/drawing.c