set AVAILABLE_STORAGE_BUFFER_BINDINGS to the actual number of buffers available (bevyengine#6787)

# Objective

- Since bevyengine#5900 3d examples fail in wasm
```
ERROR crates/bevy_render/src/render_resource/pipeline_cache.rs:660 failed to process shader: Unknown shader def: 'AVAILABLE_STORAGE_BUFFER_BINDINGS'
```

## Solution

- Fix it by always adding the shaderdef `AVAILABLE_STORAGE_BUFFER_BINDINGS` with the actual value, instead of 3 when 3 or more were available

Author: mockersf

crates/bevy_render/src/render_resource/pipeline_cache.rs

@@ -19,9 +19,7 @@ use bevy_utils::{
 };
 use std::{hash::Hash, iter::FusedIterator, mem, ops::Deref};
 use thiserror::Error;
-use wgpu::{
-    BufferBindingType, PipelineLayoutDescriptor, VertexBufferLayout as RawVertexBufferLayout,
-};
+use wgpu::{PipelineLayoutDescriptor, VertexBufferLayout as RawVertexBufferLayout};
 
 use crate::render_resource::resource_macros::*;
 
@@ -178,17 +176,10 @@ impl ShaderCache {
                     shader_defs.push("SIXTEEN_BYTE_ALIGNMENT".into());
                 }
 
-                // 3 is the value from CLUSTERED_FORWARD_STORAGE_BUFFER_COUNT declared in bevy_pbr
-                // Using the value directly here to avoid the cyclic dependency
-                if matches!(
-                    render_device.get_supported_read_only_binding_type(3),
-                    BufferBindingType::Storage { .. }
-                ) {
-                    shader_defs.push(ShaderDefVal::Int(
-                        String::from("AVAILABLE_STORAGE_BUFFER_BINDINGS"),
-                        3,
-                    ));
-                }
+                shader_defs.push(ShaderDefVal::Int(
+                    String::from("AVAILABLE_STORAGE_BUFFER_BINDINGS"),
+                    render_device.limits().max_storage_buffers_per_shader_stage as i32,
+                ));
 
                 debug!(
                     "processing shader {:?}, with shader defs {:?}",