JP-3494: write tweakreg source catalogs into user-specified output_dir

[emolter]

Resolves JP-3494

Closes #8144

This PR addresses an issue where the output_dir parameter was not respected when writing source catalogs in the tweakreg step.

Checklist for maintainers

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

[emolter]

started regression tests here

[codecov]

Codecov Report

Attention: Patch coverage is 52.94118% with 8 lines in your changes are missing coverage. Please review.

Project coverage is 75.67%. Comparing base (2fb073e) to head (2c9854e).
Report is 21 commits behind head on master.

❗ Current head 2c9854e differs from pull request most recent head d310235. Consider uploading reports for the commit d310235 to get more accurate results

Files	Patch %	Lines
jwst/tweakreg/tweakreg_step.py	52.94%	8 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #8386      +/-   ##
==========================================
+ Coverage   75.31%   75.67%   +0.36%     
==========================================
  Files         474      476       +2     
  Lines       38965    39439     +474     
==========================================
+ Hits        29345    29845     +500     
+ Misses       9620     9594      -26     

Flag	Coverage Δ		*Carryforward flag
nightly	77.66% <ø> (+0.32%)	⬆️	Carriedforward from 2fb073e

*This pull request uses carry forward flags. Click here to find out more.

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[hbushouse]

Could use another regtest run. The first one was messed up by dependencies not being synched up properly while in the midst of getting ready for the b10.2 release.

[hbushouse]

Code updates look good to me. Just holding final approval until there's a more recent regtest run to look at.

[emolter]

new regtest run started here

[hbushouse]

Failures in latest regtest run are all benign and unrelated to this PR.