JP-3628: Revise coron3 alignment step

[penaguerrero]

Resolves JP-3628

Closes #

This PR addresses aligning only the first integration of the science exposure.

Checklist for PR authors (skip items if you don't have permissions or they are not applicable)

• [x] added entry in CHANGES.rst within the relevant release section
• [x] updated or added relevant tests
• [x] updated relevant documentation
• [x] added relevant milestone
• [x] added relevant label(s)
• [x] ran regression tests, post a link to the Jenkins job below. How to run regression tests on a PR
• [x] All comments are resolved
• [x] Make sure the JIRA ticket is resolved properly

[penaguerrero]

reg tests: https://plwishmaster.stsci.edu:8081/job/RT/job/JWST-Developers-Pull-Requests/1602/

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 81.81818% with 2 lines in your changes missing coverage. Please review.

Project coverage is 60.47%. Comparing base (cf91724) to head (0dae781).

Files with missing lines	Patch %	Lines
jwst/coron/imageregistration.py	81.81%	2 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #8643 +/- ## ======================================= Coverage 60.47% 60.47% ======================================= Files 369 369 Lines 38408 38413 +5 ======================================= + Hits 23226 23230 +4 - Misses 15182 15183 +1 ```

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[melanieclarke]

@penaguerrero - I'm not sure your solution here does what is required. It looks like you are computing the shifts from the first integration, as requested, but then you are shifting only the first integration. I think the shifts computed from the first integration need to be applied to all the subsequent ones.

[penaguerrero]

@melanieclarke thanks! brain freeze :)

[penaguerrero]

reg test: https://plwishmaster.stsci.edu:8081/job/RT/job/JWST-Developers-Pull-Requests/1625/