`unregister_setting()` does not remove default option filter

[flixos90]

When using register_setting() and providing a 'default' value, that value is set as the default for get_option() calls using a filter. However, when using unregister_setting() for such a setting, the filter hook is not removed again. This seems like an oversight and should be fixed.

For reference, the functionality was introduced in [38910].

[flixos90]

I just noticed this is not as critical as I had initially thought. Since the setting will not be registered anymore, the filter won't change anything. Regardless, it's redundant that way, so it should be removed again.

43207.diff​ adds a patch with a test.

[flixos90]

In 42655:

Options: Unhook default option filter when setting is unregistered.

Fixes #43207.

[johnbillion]

In 42659:

Options: Use more appropriate language in the test suite.

See #43207, #38176

[jorbin]

In 42663:

Options: Use most appropriate language in the test suite.

The test suite's opinion of cancer should be clear.

Reverts r42659.

See #43207, #38176

[helen]

Replying to jorbin:

In 42663:

Options: Use most appropriate language in the test suite.

The test suite's opinion of cancer should be clear.

Reverts r42659.

See #43207, #38176

I have discussed this with both involved parties and will be reverting this revert. There will be no further back-and-forth via commits without documented discussion. I will also be reviewing our documentation around communication and ensuring that our socially-understood guideline of family-friendly, non-profane language in open project communication is also a written one. This is indeed a small thing for a lead to pull her lead card on, but here we are.

[helen]

In 42667:

Options: Use strings in the test suite that follow community guidelines.

Also somewhat explain to future maintainers why this pairing of strings was chosen, besides this committer's musical preferences. Social opinions on cancer are fairly clear, as are commonly accepted definitions of profanity and family-friendly language.

Shout out to the close contender, which would have been particularly appropriate here: "You could be the king But watch the queen conquer".

see #43207, #38176