graphics/libplacebo: unbreak GLSLANG=on after 1801dc2

compiler.find_library(static: true) ignores LDFLAGS and LIBRARY_PATH
as Meson uses --print-search-dirs instead of trying to link.

src/glsl/meson.build:34:4: ERROR: C++ static library 'SPIRV' not found
src/glsl/meson.build:45:12: ERROR: C++ static library 'MachineIndependent' not found

PR:		270221
Reported by:	Philipp Ost
Regressed by:	https://code.videolan.org/videolan/libplacebo/-/commit/980f2574aa0f

graphics/libplacebo/Makefile

@@ -54,6 +54,9 @@ VULKAN_MESON_ENABLED=	vulkan
 post-patch:
 	@${REINPLACE_CMD} -e 's,/usr/share,${PREFIX}/share,' \
 		${WRKSRC}/src/vulkan/utils_gen.py
+# https://github.com/mesonbuild/meson/issues/7746
+	@${REINPLACE_CMD} "s,static:,dirs: '${LOCALBASE}/lib'\, &," \
+		${WRKSRC}/src/glsl/meson.build
 # Extract (snapshot) version from port version instead of meson.build
 	@${REINPLACE_CMD} "s/version_pretty/'${DISTVERSIONFULL}'/" \
 		${WRKSRC}/src/meson.build