JP-3127: Fix bounding box in MRS TSO observations

[nden]

Resolves JP-3127

This PR fixes a problem with the computation of the bounding box of a MIRI MRS TSO observation. The bounding box is defined by the shape of the data. The code assumed an MRS observation, the input to assign_wcs is always a 2D image and used the shape of the data array in a simplistic way to determine the bounding box. Since TSO observations are cubes this created very small bounding boxes. Fixed by calling the correct function, transform_bbox_from_shape, already available in assign_wcs/utils.py

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

[codecov]

Codecov Report

Patch coverage: 100.00% and project coverage change: -0.01 ⚠️

Comparison is base (08b318e) 77.60% compared to head (7cf502a) 77.59%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #7492      +/-   ##
==========================================
- Coverage   77.60%   77.59%   -0.01%     
==========================================
  Files         452      452              
  Lines       36095    36094       -1     
==========================================
- Hits        28010    28008       -2     
- Misses       8085     8086       +1     

Flag	Coverage Δ
nightly	77.60% <100.00%> (-0.01%)	⬇️
unit	49.56% <100.00%> (-0.01%)	⬇️

Impacted Files	Coverage Δ
jwst/assign_wcs/miri.py	90.43% <100.00%> (-0.04%)	⬇️

... and 1 file with indirect coverage changes

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[hbushouse]

Looks good to me. Maybe a brief (1 or 2 sentence) description of what the problem was and how it's been fixed would be nice in the description section of the ticket.

[hbushouse]

Regtest run started at https://plwishmaster.stsci.edu:8081/job/RT/job/JWST-Developers-Pull-Requests/601

Whoops, forgot to pin the CRDS context for run 601, so it tried to run snowball flagging without opencv being installed. I've started another run with context pinned to 1062, so that snowball doesn't run:
https://plwishmaster.stsci.edu:8081/job/RT/job/JWST-Developers-Pull-Requests/602

[hbushouse]

Regtest run https://plwishmaster.stsci.edu:8081/job/RT/job/JWST-Developers-Pull-Requests/606/ using context 1068 shows 6 expected differences in MRS TSO results. Looks good.