Function is_dispatch_enabled 

pub fn is_dispatch_enabled() -> bool

Whether per-DISPATCH profiling is enabled via MLX_PROFILE_DISPATCH=1.

Cached in an atomic so the hot path is a single load — same gating semantics as is_enabled. When set, the per-CB profile is also force-enabled (so cross-validation per Risk R3 is always possible) — see [is_enabled_or_dispatch].