Warn about using the GC

[claptrap]

On Sunday, 14 January 2024 at 12:19:12 UTC, Sergey wrote:
> On Sunday, 14 January 2024 at 10:49:44 UTC, Siarhei Siamashka 
> wrote:
>> Too bad that Walter is most likely already fixated on his own 
>> idea and is in a "tunnel vision" mode, turning a blind eye on 
>> real practical use cases. Now he will defend his contraption 
>> to the bitter end. Don't expect him to pay any attention to 
>> the opinion of lowly plebeians. We are only allowed to cheer 
>> on him and praise his great talent.
>
> more users for OpenD… so the transition may become the reality..

Except they seem even more keen on killing @nogc.