Build Ghostty for x86_64 with pinned Zig toolchain

pkgbuilds/ghostty/build-data-llvm.patch

@@ -0,0 +1,10 @@
+--- a/src/build/GhosttyResources.zig
++++ b/src/build/GhosttyResources.zig
+@@ -15,6 +15,7 @@
+     // This is the exe used to generate some build data.
+     const build_data_exe = b.addExecutable(.{
+         .name = "ghostty-build-data",
++        .use_llvm = true,
+         .root_module = b.createModule(.{
+             .root_source_file = b.path("src/main_build_data.zig"),
+             .target = b.graph.host,