### Godot version

4.0.beta16

### System information

Windows 10 Pro x64, GLES3, RTX 3080 Ti (528.02)

### Issue description

In Compatibility/GLES3 back-end, shaders which use a uniform to get the normal roughness buffer cannot compile. For example, the shader:
```glsl
shader_type spatial;

uniform sampler2D normal_roughness_texture : hint_normal_roughness_texture;

void fragment() {
    vec4 sample = texture(normal_roughness_texture, UV);
}
```
results in an error in the output:
```
  drivers/gles3/shader_gles3.cpp:242 - SceneShaderGLES3: Fragment shader compilation failed:
  0(890) : error C1503: undefined variable "normal_roughness_buffer"
  
  drivers/gles3/shader_gles3.cpp:342 - Method/function failed.
```

If I switch over to the Mobile or Forward+ backends, there is no shader compilation error.

### Steps to reproduce

Open the attached reproduction in the 4.0.beta16 editor.

When the scene is opened, the error is produced automatically:
1. Open `scene.tscn`
2. Open Output to review error

When the scene is saved with any changes made to the shader, the same error is also produced:
1. Open `scene.tscn`
2. Open `example.gdshader` in the shader editor.
3. Make a compile-able change to the shader.
4. Save the scene
5. Open Output to review the error

### Minimal reproduction project

[NormalRoughnessTexture_GLES3_Error.zip](https://github.com/godotengine/godot/files/10534253/NormalRoughnessTexture_GLES3_Error.zip)

return check_warnings;
}
void ShaderLanguage::set_warning_flags(uint32_t p_flags) {
	warning_flags = p_flags;
}
uint32_t ShaderLanguage::get_warning_flags() const {
	return warning_flags;
}
#endif 
Error ShaderLanguage::compile(const String &p_code, const ShaderCompileInfo &p_info) {
	clear();
	is_shader_inc = p_info.is_include;
	code = p_code;
	global_shader_uniform_get_type_func = p_info.global_shader_uniform_type_func;
	varying_function_names = p_info.varying_function_names;
	nodes = nullptr;
	shader = alloc_node<ShaderNode>();
	Error err = _parse_shader(p_info.functions, p_info.render_modes, p_info.shader_types);
#ifdef DEBUG_ENABLED
	if (check_warnings) {
		_check_warning_accums();
	}
#endif 
	if (err != OK) {
		return err;
	}
	return OK;
}
Error ShaderLanguage::complete(const String &p_code, const ShaderCompileInfo &p_info, List<ScriptLanguage::CodeCompletionOption> *r_options, String &r_call_hint) {