Remove misleading assume example.

[abeakkas]

Given snippet doesn't find any satisfying examples anymore. Not sure if it can be fixed through tweaking some settings but it is misleading in its current state. I don't know what changed since the original documentation was added, maybe @DRMacIver can comment.

See the relevant PR:
#2600
which was mistakenly reverted in:
#3238

[DRMacIver]

Huh it's hard to see how this example would ever have passed in modern Hypothesis. I wonder how old it is - I think some of the early versions had features that might have allowed it to pass, but I think it's probably been broken since 3.0 came out. Thanks for the catch!

[DRMacIver]

I think this section is a bit confusing with this example just straightforwardly deleted, and the example should be retained but with the actual error message produced and an explanation that this demonstrates the limitations of assume, suggesting rewriting it to use lists(integers(min_value=0), min_size=11) instead of the assume.

[Zac-HD]

I'm happy to merge this as-is; it reads well enough to be an improvement on the status quo IMO and it's not like we have a surplus of documentation contributors 😅

Thanks for the patch, @abeakkas!