Bump tensorflow

Bumps the pip group with 1 update in the /paxml/pip_package directory: [tensorflow](https://github.com/tensorflow/tensorflow).


Updates `tensorflow` from 2.9.3 to 2.12.1
- [Release notes](https://github.com/tensorflow/tensorflow/releases)
- [Changelog](https://github.com/tensorflow/tensorflow/blob/master/RELEASE.md)
- [Commits](tensorflow/tensorflow@v2.9.3...v2.12.1)

---
updated-dependencies:
- dependency-name: tensorflow
  dependency-type: direct:production
  dependency-group: pip
...

Signed-off-by: dependabot[bot] <[email protected]>

paxml/pip_package/requirements.txt

@@ -658,7 +658,7 @@ tensorboard-data-server==0.6.1
     # via tensorboard
 tensorboard-plugin-wit==1.8.1
     # via tensorboard
-tensorflow==2.9.3
+tensorflow==2.12.1
     # via
     #   -r paxml-requirements.in
     #   -r praxis-requirements.in