bug#60511: 29.0.50; treesit-ready-p should not emit warning by default

[Juri Linkov]

>> >> > I think the default should be to emit a warning, like we do now.
>> >>
>> >> Then how users could change this default?
>> >
>> > In what situation?
>> >
>> > If they invoke the mode, they aren't supposed to disable the warning,
>> > and they cannot.
>>
>> In a situation when they want simply to visit a file without using
>> tree-sitter features, and that visit won't require from them
>> customization with modifying auto-mode-alist, etc.
>
> This will soon become a non-issue, as I plan on removing all the TS
> modes from auto-mode-alist.  Only loading the mode will add it back to
> the alist.  So there will be no surprises, and no need to conceal the
> warning.

Why users need to always load modes that they are using only occasionally?