return ndarray if lazy_load=False

[braingram]

Description

This PR switches the class deserialized from ndarray tags when lazy_load=False from NDArrayType to ndarray. I'm going to claim this is a "bugfix" and not a breaking change. With this PR (assuming "foo.asdf" has an array at "my_arr"):

import asdf
import numpy as np
af = asdf.open("foo.asdf", lazy_load=False)
assert type(af["my_arr"]) is np.ndarray

passes as does:

import asdf
import numpy as np
af = asdf.open("foo.asdf", lazy_tree=True, lazy_load=False)
assert type(af["my_arr"]) is np.ndarray

romancal regtests all pass: https://github.com/spacetelescope/RegressionTests/actions/runs/15494657881/job/43628410532
jwst regtests: https://github.com/spacetelescope/RegressionTests/actions/runs/15494660470
show 2 unrelated failures (that are currently being oked on main)

Closes: #1787

Tasks

• run pre-commit on your machine
• run pytest on your machine
• Does this PR add new features and / or change user-facing code / API? (if not, label with no-changelog-entry-needed)
  • write news fragment(s) in changes/: echo "changed something" > changes/<PR#>.<changetype>.rst (see below for change types)
  • update relevant docstrings and / or docs/ page
  • for any new features, add unit tests

news fragment change types...

• changes/<PR#>.feature.rst: new feature
• changes/<PR#>.bugfix.rst: bug fix
• changes/<PR#>.doc.rst: documentation change
• changes/<PR#>.removal.rst: deprecation or removal of public API
• changes/<PR#>.general.rst: infrastructure or miscellaneous change