update build syntax

build.zig

@@ -19,7 +19,7 @@ pub fn build(b: *std.Build) void {
         .name = "zremap",
         // In this case the main source file is merely a path, however, in more
         // complicated build scripts, this could be a generated file.
-        .root_source_file = .{ .path = "src/main.zig" },
+        .root_source_file = b.path("src/main.zig"),
         .target = target,
         .optimize = optimize,
     });