[Bugfix][RL] Fix cross-stream reuse of packed NCCL receive buffers (#62555)
Signed-off-by: Dharak Kharod <dharak.kharod@cohere.com>
Co-authored-by: Mohit Kulkarni <mohit.kulkarni@cohere.com>
Co-authored-by: Cursor <cursoragent@cursor.com>
Co-authored-by: aoshen02 <aoshen@inferact.ai>