build: framegen can use self-hosted

This was a red herring when I was doing the 0.15 port. It works with
self-hosted just fine.

src/build/GhosttyFrameData.zig

@@ -43,7 +43,6 @@ pub fn distResources(b: *std.Build) struct {
         .root_module = b.createModule(.{
             .target = b.graph.host,
         }),
-        .use_llvm = true,
     });
     exe.addCSourceFile(.{
         .file = b.path("src/build/framegen/main.c"),