TFLite micro sync update is not correct; a moved file is now at both old and new locations.

Looking at the current TFLM sync branch: https://github.com/google/CFU-Playground/tree/d9c1645f371f6e13bfe0e4e801691bffc4e8b8e7/third_party/tflite-micro/tensorflow/lite/micro, PR #554 :

The file `simple_memory_allocator.cc` is located both under `micro/` (old location) and under `micro/arena_allocator/` (new location). The upstream TFLM repo only has it under `micro/arena_allocator/`.

If I manually remove `third_party/tflite-micro` and then run `scripts/sync_from_tflite_micro.sh`, the directory then seems correct, with the file only at the new location. So the problem might be in the Github action.

Probably related, I noticed that both `tensorflow/lite/common.c` and `tensorflow/lite/common.cc` exist:
https://github.com/google/CFU-Playground/tree/d9c1645f371f6e13bfe0e4e801691bffc4e8b8e7/third_party/tflite-micro/tensorflow/lite/c . After my manual refresh, only `common.cc` exists.
But for some reason, `common.cc` (the right one) is not getting copied to under the project `build/` directory.
Ah, we had a workaround in our `proj/proj.mk` to delete `common.cc` so that only `common.c` remained.

I have fixed the immediate issues and will push to the sync branch.
This includes updates to `proj/proj.mk` to accommodate the file location changes.

However the underlying problem, that the automatic sync leaves the old versions of files that are moved/renamed, still remains.