Add specific tensorflow package in prereqs

Addding specific tensorflow package due to
https://github.com/openxla/iree/issues/13483.

Change-Id: I3458ec9b72442e4efd03772d78f317c3c0ffdc03

python-requirements.txt

diff --git a/python-requirements.txt b/python-requirements.txt
index 93988ac..b37cf8c 100644
--- a/python-requirements.txt
+++ b/python-requirements.txt
@@ -35,5 +35,7 @@
 sel4-deps
 setuptools
 tempita
+# TODO(lundong): Update to tensorflow 2.13.0 when it is released
+tf-nightly==2.13.0.dev20230501
 wget
 yapf