Log Message:
py-asdf: updated to 2.15.1

2.15.1 (2023-08-07)
-------------------

The ASDF Standard is at v1.6.0

- Drop Python 3.8 support
- Drop NumPy 1.20, 1.21 support
- Convert numpy scalars to python types during yaml encoding
  to handle NEP51 changes for numpy 2.0
- Vendorize jsonschema 4.17.3

2.15.0 (2023-03-28)
-------------------

The ASDF Standard is at v1.6.0

- Require numpy<1.25 for python 3.8
- Add AsdfProvisionalAPIWarning to warn developers of new features that
  may undergo breaking changes but are likely to be included as stable
  features (without this warning) in a future version of ASDF
- Add AsdfDeprecationWarning to AsdfFile.blocks
- Document policy for ASDF release cycle including when support for ASDF versions
  end. Also document dependency support policy.
- Update lower pins on ``numpy`` (per release policy), ``packaging``, and \ 
``pyyaml`` to
  ones that we can successfully build and test against.
- Provide more informative filename when failing to open a file
- Add new plugin type for custom schema validators.
- Add AsdfDeprecationWarning to `~asdf.types.CustomType`
- Throw more useful error when provided with a path containing an
  extra leading slash
- Add AsdfDeprecationWarning to AsdfInFits. Support for reading and
  writing ASDF in fits files is being moved to `stdatamodels
  <https://github.com/spacetelescope/stdatamodels>`_.
- Add AsdfDeprecationWarning to asdf.resolver
- Add AsdfDeprecationWarning to asdf.tests.helpers.assert_extension_correctness
- Add AsdfDeprecationWarning to asdf.type_index
- Add warning to use of asdftool extract and remove-hdu about deprecation
  and impending removal
- Deprecate AsdfFile attributes that use the legacy extension api
- Add AsdfDeprecationWarning to asdf.types
- deprecate default_extensions, get_default_resolver and
  get_cached_asdf_extension_list in asdf.extension
- move asdf.types.format_tag to asdf.testing.helpers.format_tag
- Deprecate AsdfExtenion, AsdfExtensionList, BuiltinExtension
- Add AsdfDeprecationWarning to asdf_extensions entry point
- Deprecate asdf.tests.helpers
- respect umask when determining file permissions for written files
- rename master branch to main