Just use a for loop in the cohesion function

I was trying to work out a way to run the loop using iterators, but
that doesn't really matter. I had an empty loop to consume the results,
which means I just have a for loop anyway.

src/birdoids_plugin.rs

@@ -159,8 +159,7 @@ fn cohesion(
     boids: Query<&Transform, With<Boid>>,
     mut velocities: Query<&mut Velocity, With<Boid>>,
 ) {
-    let it = boids.iter()
-        .map(|transform| {
+    for transform in &boids {
         let neighbors = spatial_tree.within_distance(
             transform.translation.xy(),
             BOID_VIEW_RANGE
@@ -175,8 +174,5 @@ fn cohesion(
                 **velocity += towards.extend(0.0) * COHESION_FACTOR;
             }
         }
-        });
-    for _ in it{
-        continue;
     }
 }