JP-3622 Update refpix step for NIR detectors to use convolution kernel

[penaguerrero]

Resolves JP-3622
Resolves RCAL-nnnn

Closes #

This PR addresses the changes needed to read a reference file for the NIR Optimized Convolution Kernel to be applied at the REFPIX step in the Detector1 pipeline.

Checklist

• added entry in CHANGES.rst (either in Bug Fixes or Changes to API)
• updated relevant tests
• updated relevant documentation
• updated relevant milestone(s)
• added relevant label(s)

[codecov]

Codecov Report

Attention: Patch coverage is 83.33333% with 2 lines in your changes missing coverage. Please review.

Project coverage is 66.59%. Comparing base (fd6be8d) to head (1d3f3fe).
Report is 6 commits behind head on main.

Files with missing lines	Patch %	Lines
src/stdatamodels/jwst/datamodels/conv_kernel.py	81.81%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #321      +/-   ##
==========================================
+ Coverage   66.55%   66.59%   +0.04%     
==========================================
  Files         102      103       +1     
  Lines        5456     5469      +13     
==========================================
+ Hits         3631     3642      +11     
- Misses       1825     1827       +2     

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