### 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)

completion_class = TAG_GLOBAL;
	completion_struct = StringName();
	completion_base = TYPE_VOID;
	completion_base_array = false;
	include_positions.clear();
	include_positions.push_back(FilePosition());
#ifdef DEBUG_ENABLED
	keyword_completion_context = CF_UNSPECIFIED;
	used_constants.clear();
	used_varyings.clear();
	used_uniforms.clear();
	used_functions.clear();
	used_structs.clear();
	used_local_vars.clear();
	warnings.clear();
#endif 
	error_line = 0;
	tk_line = 1;
	char_idx = 0;
	error_set = false;
	error_str = "";
	last_const = false;
	while (nodes) {
		Node *n = nodes;
		nodes = nodes->next;
		memdelete(n);
	}
}
#ifdef DEBUG_ENABLED
void ShaderLanguage::_parse_used_identifier(const StringName &p_identifier, IdentifierType p_type, const StringName &p_function) {