switch convert_unknown_ndarray_subclasses to False

[braingram]

Description

Switches the default value for convert_unknown_ndarray_subclasses to False and issues an AsdfDeprecationWarning if this setting is enabled. We can remove it in asdf 5.0.

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

[braingram]

Running jwst regtests as fitsrec was the motivation for this setting: https://github.com/spacetelescope/RegressionTests/actions/runs/11616650882

EDIT: these ran with only 1 unrelated failure (same as on main)

[nden]

LGTM. Left a couple comments.

[nden]

Does this count as an API change? I'm not sure how asdf deals with changes like this and I don't know if there are any cases in practice that will be affected.

[braingram]

I agree this counts as an API change.

When this feature was introduced (3.0.0) a warning was also added:

asdf/asdf/yamlutil.py

Lines 305 to 310 in abeef0e

	warnings.warn(
	f"A ndarray subclass ({type(obj)}) was converted as a ndarray. "
	"This behavior will be removed from a future version of ASDF. "
	"See https://asdf.readthedocs.io/en/latest/asdf/config.html#convert-unknown-ndarray-subclasses",
	AsdfConversionWarning,
	)

and a section in the linked docs:

In a future version of asdf this default will change to False, a deprecation warning will be issued and finally the conversion of instances of subclasses will be removed.

We are now in the future! This PR adds the deprecation warning and asdf 5.0.0 we can remove the setting and the behavior.

[braingram]

I opened an issue to track adding this to "what's new": #1865