fix: cloze_numbers_in_string treating {{c0::}} as valid

[BrayanDSO]

cloze_numbers_in_string and consequently cloze_numbers_in_note returned the zero of {{c0::}}, although they shouldn't

[dae]

@BrayanDSO mind elaborating on what issue the current code was causing?

@abdnh Will this change cause problems for the text annotations in I/O?

[BrayanDSO]

@BrayanDSO mind elaborating on what issue the current code was causing?

Note.cloze_numbers_in_fields, which is an available method for Add-on creators, has 0 among the returned result if {{c0::}} is present in the card, although it shouldn't.

anki/pylib/anki/notes.py

Lines 137 to 138 in 6ac60f8

	def cloze_numbers_in_fields(self) -> Sequence[int]:
	return self.col._backend.cloze_numbers_in_note(self._to_backend_note())

Also, it is a current cause of an issue in AnkiDroid if {{c0::}} is present when a card is previewed because of the faulty return value of cloze_numbers_in_note

Can I just remove it from the returned result? Yes, but fixing the root cause is the appropriate solution IMO

---

also, I'm not sure if this will implicate in any problems with IO since I'm not very proefficient with Rust/Anki codebase

[dae]

I'm not sure there's a "right" answer here - I suspect you could make a case for 0 being excluded here, or at a different layer instead. If it doesn't break anything, I don't have any objections. Will be interested to hear from @abdnh.

[abdnh]

@abdnh Will this change cause problems for the text annotations in I/O?

It won't cause problems.

[dae]

Thank you both!