Use the safer `safe_load` function instead of `unsafe_load` when poss…

…ible

There is no need to open ourselves up to arbitrary code execution, especially since this is not in a performance critical loop, so we can take the slowdown due to safety.

PiperOrigin-RevId: 388501098

Use the safer `safe_load` function instead of `unsafe_load` when poss…

…ible

There is no need to open ourselves up to arbitrary code execution, especially since this is not in a performance critical loop, so we can take the slowdown due to safety.

PiperOrigin-RevId: 388501098

Add more explicit error message for instance type checking of optimizer.

PiperOrigin-RevId: 382409145

Internal change

PiperOrigin-RevId: 382327442

Add ParameterServerStrategy combination to ketrics_metrics_test.

PiperOrigin-RevId: 381424814

Redirect Keras to tf.keras (keras-team#14121)

* Replace all code with tf.keras redirects

Prepare 2.3.1 release

Update README

Fix sklearn regressor test?

Prepare 2.2.4 release.