graphics/igt-gpu-tools: unbreak with --auto-features=enabled

meson.build:132:0: ERROR: Dependency "valgrind" not found, tried pkgconfig

PR:		270361
Reported by:	antoine (via exp-run)

graphics/igt-gpu-tools/Makefile

@@ -31,6 +31,7 @@ USE_LDCONFIG=	yes
 USE_XORG=	pixman
 
 SHEBANG_FILES=	scripts/code_cov_gather_on_test scripts/code_cov_parse_info
+MESON_ARGS=	-Dvalgrind=disabled
 
 OPTIONS_DEFINE=		CHAMELIUM DOCS RUNNER TEST
 OPTIONS_DEFAULT=	DOCS RUNNER TEST