Significantly reduce the amount of building required for benchmarks (#4067)

# Objective

- Release mode. Many time

## Solution

- Less things, less time

benches/Cargo.toml

@@ -8,7 +8,8 @@ license = "MIT OR Apache-2.0"
 
 [dev-dependencies]
 criterion = "0.3"
-bevy = { path = ".." }
+bevy_ecs = { path = "../crates/bevy_ecs" }
+bevy_tasks = { path = "../crates/bevy_tasks" }
 
 [[bench]]
 name = "system_stage"

benches/benches/bevy_ecs/commands.rs

@@ -1,4 +1,4 @@
-use bevy::ecs::{
+use bevy_ecs::{
     component::Component,
     entity::Entity,
     system::{Command, CommandQueue, Commands},

benches/benches/bevy_ecs/stages.rs

@@ -1,4 +1,4 @@
-use bevy::ecs::{
+use bevy_ecs::{
     component::Component,
     schedule::{Stage, SystemStage},
     system::Query,

benches/benches/bevy_ecs/world_get.rs

@@ -1,4 +1,4 @@
-use bevy::ecs::{component::Component, entity::Entity, world::World};
+use bevy_ecs::{component::Component, entity::Entity, world::World};
 use criterion::{black_box, criterion_group, criterion_main, Criterion};
 
 criterion_group!(

benches/benches/bevy_tasks/iter.rs

@@ -1,4 +1,4 @@
-use bevy::tasks::{ParallelIterator, TaskPoolBuilder};
+use bevy_tasks::{ParallelIterator, TaskPoolBuilder};
 use criterion::{black_box, criterion_group, criterion_main, BenchmarkId, Criterion};
 
 struct ParChunks<'a, T>(std::slice::Chunks<'a, T>);