Merge "script: Update tf-nightly to the latest one"

python-requirements.txt

diff --git a/python-requirements.txt b/python-requirements.txt
index 326d72a..20158c4 100644
--- a/python-requirements.txt
+++ b/python-requirements.txt
@@ -38,6 +38,6 @@
 sel4-deps
 setuptools
 # TODO(lundong): not pin nightly after TOSA features are in release ver.
-tf-nightly==2.15.0.dev20230817
+tf-nightly==2.15.0.dev20230919
 wget
 yapf