[OpenVINO backend] Added support for numpy.hstack

[Imokut]

Please review @rkazants #29361

[codecov-commenter]

Codecov Report

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

Project coverage is 80.02%. Comparing base (37e2177) to head (728d1a7).

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

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #21013      +/-   ##
==========================================
- Coverage   82.45%   80.02%   -2.43%     
==========================================
  Files         562      562              
  Lines       53662    53672      +10     
  Branches     8325     8327       +2     
==========================================
- Hits        44247    42953    -1294     
- Misses       7377     8735    +1358     
+ Partials     2038     1984      -54     

Flag	Coverage Δ
keras	79.85% <0.00%> (-2.42%)	⬇️
keras-jax	63.69% <0.00%> (-0.02%)	⬇️
keras-numpy	58.66% <0.00%> (-0.02%)	⬇️
keras-openvino	?
keras-tensorflow	64.14% <0.00%> (-0.02%)	⬇️
keras-torch	63.74% <0.00%> (-0.02%)	⬇️

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[Imokut]

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