Change owners of test/test_transformers.py to module: multi-headed-at…

…tention (pytorch#132519)

So flaky tests get tagged with `module: multi-headed-attention` instead of `module: nn`

Pull Request resolved: pytorch#132519
Approved by: https://github.com/Skylion007

test/test_transformers.py

@@ -1,4 +1,4 @@
-# Owner(s): ["module: nn"]
+# Owner(s): ["module: multi-headed-attention"]
 
 import contextlib
 from functools import partial