Tf-shell

Downgrade TensorFlow dependency to 2.15.0 for use with tensorflow-privacy python package.

**Full Changelog**: https://github.com/google/tf-shell/compare/v0.1.4...v0.1.5

New features:
- Encrypted segment sum and embedding layer.
- Faster rotation protocol.
- Plaintext-plaintext graph compiler optimization pass.
- Automated parameter generation optimization pass.

Disable builds with Python 3.12 due to TensorFlow dependency on distutils.

**Full Changelog**: https://github.com/google/tf-shell/compare/v0.1.2...v0.1.4

- Zero copy broadcasting.
- HE-specific graph optimizations.
- Better autograph support.

What's Changed
* Version 0.1.3 by james-choncholas in https://github.com/google/tf-shell/pull/10


**Full Changelog**: https://github.com/google/tf-shell/compare/v0.1.2...v0.1.3

**Full Changelog**: https://github.com/google/tf-shell/compare/v0.1.1...v0.1.2