Update on "[ExecuTorch] Remove unneeded FFHT files"

We are just using FFHT to generate a kernel, so we don't need
the Python wrapper.

Differential Revision: [D60194971](https://our.internmc.facebook.com/intern/diff/D60194971/)

[ghstack-poisoned]

Author: swolchok

extension/llm/custom_ops/spinquant/fast_hadamard_transform.cpp

@@ -8,6 +8,8 @@
 
 #include "fast_hadamard_transform.h"
 
+#include <algorithm>
+
 namespace executorch {
 namespace {
 // Normalization step: divide by sqrt(1 << log2_vec_size). Similar