[OpenVino BackEnd] support np.log2 for ov BackEnd

[chiruu12]

I have added support for numpy.log2 in the OpenVINO backend
This PR is related to openvinotoolkit/openvino#29488
@rkazants could you please review

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 0% with 10 lines in your changes missing coverage. Please review.

Project coverage is 79.97%. Comparing base (6e688ab) to head (be90457).

Files with missing lines	Patch %	Lines
keras/src/backend/openvino/numpy.py	0.00%	10 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #21048      +/-   ##
==========================================
- Coverage   82.47%   79.97%   -2.51%     
==========================================
  Files         563      563              
  Lines       53834    53844      +10     
  Branches     8359     8360       +1     
==========================================
- Hits        44401    43061    -1340     
- Misses       7392     8798    +1406     
+ Partials     2041     1985      -56     

Flag	Coverage Δ
keras	79.79% <0.00%> (-2.50%)	⬇️
keras-jax	63.78% <0.00%> (-0.02%)	⬇️
keras-numpy	58.74% <0.00%> (-0.02%)	⬇️
keras-openvino	?
keras-tensorflow	64.10% <0.00%> (-0.02%)	⬇️
keras-torch	63.82% <0.00%> (-0.02%)	⬇️

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