### Godot version

v4.2.beta1.official [b1371806a]

### System information

Ubuntu 22.04.3 LTS 22.04 - X11 - GLES3 (Compatibility) - AMD Radeon RX 560 Series (polaris11, LLVM 15.0.7, DRM 3.42, 5.15.0-88-generic) () - AMD Ryzen 3 1200 Quad-Core Processor (4 Threads)

### Issue description

![image](https://github.com/godotengine/godot/assets/1330325/7a986599-5a68-42a4-beb1-5d3b4bf7db6b)
![image](https://github.com/godotengine/godot/assets/1330325/e8b8546b-b47b-4add-9567-7f70709ab03c)

Culling 3D goes bellow 60 fps even with just about 50 simple animated models. With v4.2.dev6.official [57a6813bb] many more models can be spawned without fps drop. However, both versions do show high cpu usage for culling 3D. Without animations there's barely any usage.

### Steps to reproduce

Spawn models with animation with the Compatibility renderer.

### Minimal reproduction project

[CullMRP.zip](https://github.com/godotengine/godot/files/13400514/CullMRP.zip)

ShaderLanguage::TYPE_VEC4, 
		ShaderLanguage::TYPE_VEC4, 
		ShaderLanguage::TYPE_MAX, 
		ShaderLanguage::TYPE_MAX, 
		ShaderLanguage::TYPE_MAX, 
		ShaderLanguage::TYPE_MAX, 
		ShaderLanguage::TYPE_VEC4 
	};
	ShaderLanguage::DataType datatype = ShaderLanguage::TYPE_MAX;
	if (value_type == Variant::INT && p_flags_count > 0) {
		switch (p_flags_count) {
			case 1:
				datatype = ShaderLanguage::TYPE_BVEC2;
				break;
			case 2:
				datatype = ShaderLanguage::TYPE_BVEC3;
				break;
			case 3:
				datatype = ShaderLanguage::TYPE_BVEC4;
				break;
		}
	} else {
		datatype = datatype_from_value[value_type];
	}
	ERR_FAIL_COND_MSG(datatype == ShaderLanguage::TYPE_MAX, "Unsupported variant type for instance parameter: " + Variant::get_type_name(value_type)); 
	pos += p_index;
	_fill_std140_variant_ubo_value(datatype, 0, p_value, (uint8_t *)&global_shader_uniforms.buffer_values[pos]);
	_global_shader_uniform_mark_buffer_dirty(pos, 1);
}
void MaterialStorage::_update_global_shader_uniforms() {