Astrometry.net: Improvements to API key warnings/errors

[astrofrog]

Possible fix for https://github.com/astropy/astroquery/issues/2482 - only raise an error about missing API key when it is needed, otherwise user doesn't have chance to set it before the warning is emitted.

[codecov[bot]]

Codecov Report

Merging #2483 (ed1f080) into main (b1fcfff) will decrease coverage by 0.01%. The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #2483      +/-   ##
==========================================
- Coverage   62.92%   62.91%   -0.02%     
==========================================
  Files         133      133              
  Lines       17302    17308       +6     
==========================================
+ Hits        10888    10889       +1     
- Misses       6414     6419       +5     

Impacted Files	Coverage Δ
astroquery/astrometry_net/core.py	47.64% <100.00%> (-2.36%)	:arrow_down:
astroquery/alma/core.py	43.35% <0.00%> (+0.55%)	:arrow_up:

:mega: We’re building smart automated test selection to slash your CI/CD build times. Learn more

[bsipocz]

Thanks @astrofrog!

[astrofrog]

Thanks for wrapping this up @bsipocz!