Remove unused code in game of life shader (#5349)

# Objective

- Make `game_of_life.wgsl` easier to read and understand

## Solution

- Remove unused code in the shader
    - `location_f32` was unused in `init`
    - `color` was unused in `update`

assets/shaders/game_of_life.wgsl

@@ -11,14 +11,14 @@ fn hash(value: u32) -> u32 {
     state = state * 2654435769u;
     return state;
 }
+
 fn randomFloat(value: u32) -> f32 {
     return f32(hash(value)) / 4294967295.0;
 }
 
 @compute @workgroup_size(8, 8, 1)
 fn init(@builtin(global_invocation_id) invocation_id: vec3<u32>, @builtin(num_workgroups) num_workgroups: vec3<u32>) {
     let location = vec2<i32>(i32(invocation_id.x), i32(invocation_id.y));
-    let location_f32 = vec2<f32>(f32(invocation_id.x), f32(invocation_id.y));
 
     let randomNumber = randomFloat(invocation_id.y * num_workgroups.x + invocation_id.x);
     let alive = randomNumber > 0.9;
@@ -27,7 +27,6 @@ fn init(@builtin(global_invocation_id) invocation_id: vec3<u32>, @builtin(num_wo
     textureStore(texture, location, color);
 }
 
-
 fn is_alive(location: vec2<i32>, offset_x: i32, offset_y: i32) -> i32 {
     let value: vec4<f32> = textureLoad(texture, location + vec2<i32>(offset_x, offset_y));
     return i32(value.x);
@@ -49,7 +48,6 @@ fn update(@builtin(global_invocation_id) invocation_id: vec3<u32>) {
     let location = vec2<i32>(i32(invocation_id.x), i32(invocation_id.y));
 
     let n_alive = count_alive(location);
-    let color = vec4<f32>(f32(n_alive) / 8.0);
 
     var alive: bool;
     if (n_alive == 3) {
@@ -60,8 +58,9 @@ fn update(@builtin(global_invocation_id) invocation_id: vec3<u32>) {
     } else {
         alive = false;
     }
+    let color = vec4<f32>(f32(alive));
 
     storageBarrier();
 
-    textureStore(texture, location, vec4<f32>(f32(alive)));
+    textureStore(texture, location, color);
 }