Fix issue 3007: offline tests should be valid

[keflavich]

This PR moves the test data to filenames that match what's actually used in the query. It fixes #3007.

[bsipocz]

CI failures are related

[codecov]

Codecov Report

Attention: Patch coverage is 33.33333% with 2 lines in your changes missing coverage. Please review.

Project coverage is 68.34%. Comparing base (3e9ff61) to head (250cd59).
Report is 333 commits behind head on main.

Files with missing lines	Patch %	Lines
astroquery/linelists/cdms/core.py	50.00%	1 Missing ⚠️
astroquery/linelists/cdms/setup_package.py	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3202      +/-   ##
==========================================
- Coverage   68.34%   68.34%   -0.01%     
==========================================
  Files         231      231              
  Lines       19190    19192       +2     
==========================================
+ Hits        13116    13117       +1     
- Misses       6074     6075       +1     

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[bsipocz]

Now this all looks good. Thanks!