py-gwcs: update to 0.21.0.

0.21.0 (2024-03-10)
-------------------

- Improve documentation. [#483]

- Add a minimum version requirement for ``asdf-wcs-schemas``. [#491]

- Fix ``WCS.__str__`` for instances without transforms. [#489]

0.20.0 (2023-11-29)
-------------------

- Replace ``pkg_resources`` with ``importlib.metadata``. [#478]

- Serialize and deserialize ``pixel_shape`` with asdf. [#480]

0.19.0 (2023-09-15)
-------------------

Bug Fixes
^^^^^^^^^

- Synchronize ``array_shape`` and ``pixel_shape`` attributes of WCS
  objects. [#439]

- Fix failures and warnings with numpy 2.0. [#472]

other
^^^^^

- Remove deprecated old ``bounding_box``. The new implementation is released with
  astropy v 5.3. [#458]

- Refactor ``CoordinateFrame.axis_physical_types``. [#459]

- ``StokesFrame`` uses now ``astropy.coordinates.StokesCoord``. [#452]

- Dropped support for Python 3.8. [#451]

- Fixed a call to ``astropy.coordinates`` in ``wcstools.wcs_from_points``. [#448]

- Code and docstrings clean up. [#460]

- Register all available asdf extension manifests from ``asdf-wcs-schemas``
  except 1.0.0 (which contains duplicate tag versions). [#469]

- Register empty extension for 1.0.0 to avoid warning about a missing
  extension when opening old files. [#475]

0.18.3 (2022-12-23)
-------------------
Bug Fixes
^^^^^^^^^

- Fixed a bug in the estimate of pixel scale in the iterative inverse
  code. [#423]

- Fixed constant term in the polynomial used for SIP fitting.
  Improved stability and accuracy of the SIP fitting code. [#427]

0.18.2 (2022-09-07)
-------------------
Bug Fixes
^^^^^^^^^

- Corrected the reported requested forward SIP accuracy and reported fit
  residuals by ``to_fits_sip()`` and ``to_fits()``. [#413, #419]

- Fixed a bug due to which the check for divergence in ``_fit_2D_poly()`` and
  hence in ``to_fits()`` and ``to_fits_sip()`` was ignored. [#414]

New Features
^^^^^^^^^^^^

0.18.1 (2022-03-15)
-------------------
Bug Fixes
^^^^^^^^^

- Remove references to the ``six`` package. [#402]

0.18.0 (2021-12-22)
-------------------
Bug Fixes
^^^^^^^^^

- Updated code in ``region.py`` with latest improvements and bug fixes
  from ``stsci.skypac.regions.py`` [#382]

- Added support to ``_compute_lon_pole()`` for computation of ``lonpole``
  for all projections from ``astropy.modeling.projections``. This also
  extends support for different projections in ``wcs_from_fiducial()``. [#389]

New Features
^^^^^^^^^^^^

- Enabled ``CompoundBoundingBox`` support for wcs. [#375]

- Moved schemas to standalone package ``asdf-wcs-schemas``.
  Reworked the serialization code to use ASDF converters. [#388]

0.17.1 (2021-11-27)
-------------------

Bug Fixes
^^^^^^^^^

- Fixed a bug with StokesProfile and array types. [#384]

0.17.0 (2021-11-17)
-------------------
Bug Fixes
^^^^^^^^^

- `world_axis_object_components` and `world_axis_object_classes` now ensure
  unique keys in `CompositeFrame` and `CoordinateFrame`. [#356]

- Fix issue where RuntimeWarning is raised when there are NaNs in coordinates
  in angle wrapping code [#367]

- Fix deprecation warning when wcs is initialized with a pipeline [#368]

- Use ``CD`` formalism in ``WCS.to_fits_sip()``. [#380]

New Features
^^^^^^^^^^^^
- ``wcs_from_points`` now includes fitting for the inverse transform. [#349]

- Generalized ``WCS.to_fits_sip`` to be able to create a 2D celestial FITS WCS
  from celestial subspace of the ``WCS``. Also, now `WCS.to_fits_sip``
  supports arbitrary order of output axes. [#357]

API Changes
^^^^^^^^^^^
- Modified interface to ``wcs_from_points`` function to better match analogous function
  in astropy. [#349]

- ``Model._BoundingBox`` was renamed to ``Model.ModelBoundingBox``. [#376, #377]

0.16.1 (2020-12-20)
-------------------
Bug Fixes
^^^^^^^^^
- Fix a regression with ``pixel_to_world`` for output frames with one axis. [#342]

0.16.0 (2020-12-18)
-------------------
New Features
^^^^^^^^^^^^

- Added an option to `to_fits_sip()` to be able to specify the reference
  point (``crpix``) of the FITS WCS. [#337]

- Added support for providing custom range of degrees in ``to_fits_sip``. [#339]

Bug Fixes
^^^^^^^^^

- ``bounding_box`` now works with tuple of ``Quantities``. [#331]

- Fix a formula for estimating ``crpix`` in ``to_fits_sip()`` so that ``crpix``
  is near the center of the bounding box. [#337]

- Allow sub-pixel sampling of the WCS model when computing SIP approximation in
  ``to_fits_sip()``. [#338]

- Fixed a bug in ``to_fits_sip`` due to which ``inv_degree`` was ignored. [#339]

(wiz)