update to latest Zig API

Signed-off-by: Stephen Gutekanst <stephen@hexops.com>

build.zig

@@ -12,7 +12,7 @@ pub fn build(b: *std.Build) void {
     });
 
     inline for (.{ "vk_video", "vulkan" }) |subdir| {
-        lib.installHeadersDirectory("include/" ++ subdir, subdir);
+        lib.installHeadersDirectory(b.path("include/" ++ subdir), subdir, .{});
     }
     b.installArtifact(lib);
 }