bump version (#332)

Author: mattnite

build.zig.zon

@@ -1,6 +1,6 @@
 .{
     .name = "microzig",
-    .version = "0.13.0",
+    .version = "0.13.1",
     .minimum_zig_version = "0.13.0",
     .dependencies = .{
         .@"build-internals" = .{ .path = "build-internals" },