Point tweakreg to new files. Move the asn file into artifactory.

[schlafly]

This updates the tweakreg regression test to use new files. It also removes the association file creation logic in favor of adding an association file to artifactory.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 73.32%. Comparing base (79586ea) to head (429a100).
Report is 515 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1012   +/-   ##
=======================================
  Coverage   73.32%   73.32%           
=======================================
  Files         103      103           
  Lines        6733     6733           
=======================================
  Hits         4937     4937           
  Misses       1796     1796           

Flag	Coverage Δ		*Carryforward flag
nightly	63.29% <ø> (ø)		Carriedforward from 79586ea

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[ddavis-stsci]

FYI: the suffix for tweakreg should be _tweakreg.asdf. The suffix _tweakregstep is the default when stpipe does not receive rules for constructing the suffix.
We can fix this later.

[schlafly]

Thanks, we'll fix that later. Merging.