Update Copyright Headers 'Facebook' -> 'Meta Platforms'

```
for f in $(find . \( -path ./.git -o -path ./tests/fuzz/corpora \) -prune -o -type f);
do
  sed -i 's/Facebook, Inc\./Meta Platforms, Inc. and affiliates./' $f;
done
```

LICENSE

@@ -2,7 +2,7 @@ BSD License
 
 For Zstandard software
 
-Copyright (c) 2016-present, Facebook, Inc. All rights reserved.
+Copyright (c) 2016-present, Meta Platforms, Inc. and affiliates. All rights reserved.
 
 Redistribution and use in source and binary forms, with or without modification,
 are permitted provided that the following conditions are met: