* convert Mixture Density Networks example to V3

[aaarrti]

Hi Keras team,
I've converted this https://keras.io/examples/keras_recipes/approximating_non_function_mappings/ example to Keras V3 and JAX backend.
The example had dependency on tensorflow_probability so it will run only TensorFlow and JAX backends 🤷 .

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 78.53%. Comparing base (a05ac12) to head (4934856).

Additional details and impacted files

@@           Coverage Diff           @@
##           master   #19733   +/-   ##
=======================================
  Coverage   78.53%   78.53%           
=======================================
  Files         498      498           
  Lines       45753    45753           
  Branches     8455     8455           
=======================================
  Hits        35933    35933           
  Misses       8086     8086           
  Partials     1734     1734           

Flag	Coverage Δ
keras	78.38% <ø> (ø)
keras-jax	61.94% <ø> (ø)
keras-numpy	56.30% <ø> (ø)
keras-tensorflow	63.42% <ø> (ø)
keras-torch	62.01% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[fchollet]

Thanks for the PR -- please create the PR at https://github.com/keras-team/keras-io/pulls instead.