Set version to 0.4.0

Author: natecraddock

build.zig.zon

@@ -1,7 +1,7 @@
 .{
     .name = .zlua,
     .fingerprint = 0xcf671dd0b696484, // changing this has security and trust implications
-    .version = "0.1.0",
+    .version = "0.4.0",
     .paths = .{ "build.zig", "build.zig.zon", "src", "license", "build" },
 
     .dependencies = .{