Add rbf_kernel Function

[tanannie22]

Description

Issue: #2313

Changes Made:

• Updated sklearnex/metrics/pairwise.py to utilize oneDAL for rbf_kernel.
• Added tests in sklearnex/metrics/tests/test_metrics.py to validate correctness.
• Added a benchmark notebook (examples/notebooks/benchmark_rbf_kernel.ipynb) to compare performance between sklearn and sklearnex.

---

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[codecov]

Codecov Report

Attention: Patch coverage is 96.15385% with 1 line in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
sklearnex/metrics/pairwise.py	96.15%	1 Missing ⚠️

Flag	Coverage Δ
azure	78.11% <92.30%> (+0.05%)	⬆️
github	?

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

Files with missing lines	Coverage Δ
sklearnex/metrics/pairwise.py	96.55% <96.15%> (-3.45%)	⬇️

... and 43 files with indirect coverage changes

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[syakov-intel]

@tanannie22 would you like to continue working on it?

[tanannie22]

@tanannie22 would you like to continue working on it?

Hi @syakov-intel, I'm still working on this, but I'm currently facing some challenges with enabling the function to compute on GPU. If you have any ideas on enabling the function to compute on GPU, it would really help me move faster. I’d appreciate any suggestions!