### 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)

op->arguments.push_back(expression[next_op + 1].node); 
			expression.write[next_op - 1].node = op;
			
			if (!_validate_operator(op, &op->return_cache, &op->return_array_size)) {
				String at;
				for (int i = 0; i < op->arguments.size(); i++) {
					if (i > 0) {
						at += ", ";
					}
					if (op->arguments[i]->get_datatype() == TYPE_STRUCT) {
						at += op->arguments[i]->get_datatype_name();
					} else {
						at += get_datatype_name(op->arguments[i]->get_datatype());
					}
					if (!op->arguments[i]->is_indexed() && op->arguments[i]->get_array_size() > 0) {
						at += "[";
						at += itos(op->arguments[i]->get_array_size());
						at += "]";
					}
				}
				_set_error(vformat(RTR("Invalid arguments to operator '%s': '%s'."), get_operator_text(op->op), at));
				return nullptr;
			}
			expression.remove_at(next_op);
			expression.remove_at(next_op);
		}
	}
	return expression[0].node;
}
ShaderLanguage::Node *ShaderLanguage::_reduce_expression(BlockNode *p_block, ShaderLanguage::Node *p_node) {