Support TF 2.15

[elad-c]

Pull Request Description:

This PR add support for TF 2.15 to MCT. The breaking change in this TF version is the function that the TFOpLambda layer holds in its function attribute. For example, before 2.15, if TFOpLambda holds a tf.add function, then the actual function in the function attribute is different than tf.add, and that messes things up.

Checklist before requesting a review:

• I set the appropriate labels on the pull request.
• I have added/updated the release note draft (if necessary).
• I have updated the documentation to reflect my changes (if necessary).
• All function and files are well documented.
• All function and classes have type hints.
• There is a licenses in all file.
• The function and variable names are informative.
• I have checked for code duplications.
• I have added new unittest (if necessary).

[ofirgo]

Can you please add a brief description to the PR specifying what were "breaking changes" that affected the MCT and what is the solution for them? just so we'll know what to look for in the review