Fix Version/s: None
This is a probable regression introduced in
DM-16819, when I tried to re-enable the test_import.py script in SCons (it looked like it was supposed to be run, but wasn't because the SConstruct wasn't talking to the SConscript because ci_hsc doesn't really use sconsUtils).
The causality was masked by a transient known download bug in Astropy.
Preferred fix worked. Merged to master without review as the fix is trivial, master is already broken, and most people are now on some kind of holiday break.