Remove deprecated pvsystem.sapm_spectral_loss

[RDaxini]

• Closes Deprecated pvsystem.sapm_spectral_loss not removed #2243
• I am familiar with the contributing guidelines
• Tests added removed
• Updates entries in docs/sphinx/source/reference for API changes.
• Adds description and name entries in the appropriate "what's new" file in docs/sphinx/source/whatsnew for all changes. Includes link to the GitHub Issue with :issue:`num` or this Pull Request with :pull:`num`. Includes contributor name and/or GitHub username (link with :ghuser:`user`).
  Wait for 12.0?
• New code is fully documented. Includes numpydoc compliant docstrings, examples, and comments where necessary.
• Pull request is nearly complete and ready for detailed review.
• Maintainer: Appropriate GitHub Labels (including remote-data) and Milestone are assigned to the Pull Request and linked Issue.

I am not super familiar with deprecations so please correct me if I have misunderstood something here or even missed an existing PR for this...

[kandersolar]

@RDaxini can you please also remove the entry in docs/sphinx/source/reference/pv_modeling/system_models.rst? With that, a what's new entry, and the merge conflict resolved, I think this will be ready to go.

[echedey-ls]

In a similar sense to my own comment, to avoid links warnings with a Sphinx builder that checks them (linkchecker, with the Option nitpick=True):

• Add exclamation to v0.6.1.rst, line 59
• Same in v0.10.0.rst, line 58

Otherwise, LGTM :D

[echedey-ls]

@RDaxini can you please also remove the entry in docs/sphinx/source/reference/pv_modeling/system_models.rst? With that, a what's new entry, and the merge conflict resolved, I think this will be ready to go.

@RDaxini can you review the changes made to docs\sphinx\source\reference\pv_modeling\system_models.rst? I think there was a confusion between the deprecated and the non-deprecated versions of the model. pvsystem.sapm_spectral_loss in line 15 should have been removed.

[kandersolar]

@RDaxini can you review the changes made to docs\sphinx\source\reference\pv_modeling\system_models.rst? I think there was a confusion between the deprecated and the non-deprecated versions of the model. pvsystem.sapm_spectral_loss in line 15 should have been removed.

Good catch @echedey-ls! I agree, the wrong one was removed. To avoid the clutter of a new PR to fix such a small thing, I'll plan to just fix that in the release finalization PR.