[EZ] Replace pytorch-labs with meta-pytorch (#9556)

This PR replaces all instances of `pytorch-labs` with `meta-pytorch` in
this repository now that the `pytorch-labs` org has been renamed to
`meta-pytorch`

## Changes Made
- Replaced all occurrences of `pytorch-labs` with `meta-pytorch`
- Only modified files with extensions: .py, .md, .sh, .rst, .cpp, .h,
.txt, .yml
- Skipped binary files and files larger than 1MB due to GitHub api
payload limits in the script to cover all repos in this org. Will do a
more manual second pass later to cover any larger files

## Files Modified
This PR updates files that contained the target text.

Generated by automated script on 2025-08-12T20:59:10.495582+00:00Z

Author: ZainRizvi

torchax/test/llama/llama_model.py

@@ -4,7 +4,7 @@
 # This source code is licensed under the license found in the
 # LICENSE file in the root directory of this source tree.
 
-# This file is copied from https://github.com/pytorch-labs/gpt-fast
+# This file is copied from https://github.com/meta-pytorch/gpt-fast
 # This is used for unit test purposes
 from dataclasses import dataclass
 import math