Returns a new vec with each value
awaited in parallel
namespace HH\Lib\Vec; function from_async<Tv>( Traversable<Awaitable<Tv>> $awaitables, ): Awaitable<vec<Tv>>;
Time complexity: O(n * a), where a is the complexity of synchronous portions of each Awaitable Space complexity: O(n)
The IO operations for each Awaitable will happen in parallel.