### 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)

}
									fixed_array_size = true;
									tk = _get_token();
								}
							}
							if (tk.type != TK_IDENTIFIER) {
								_set_error(RTR("Expected an identifier."));
								return ERR_PARSE_ERROR;
							}
							MemberNode *member = alloc_node<MemberNode>();
							member->precision = precision;
							member->datatype = type;
							member->struct_name = struct_name;
							member->name = tk.text;
							member->array_size = array_size;
							if (member_names.has(member->name)) {
								_set_redefinition_error(String(member->name));
								return ERR_PARSE_ERROR;
							}
							member_names.insert(member->name);
							tk = _get_token();
							if (tk.type == TK_BRACKET_OPEN) {
								Error error = _parse_array_size(nullptr, constants, true, nullptr, &member->array_size, nullptr);
								if (error != OK) {
									return error;
								}
								tk = _get_token();
							}
							if (!fixed_array_size) {
								array_size = 0;