### 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)

#ifdef DEBUG_ENABLED
				keyword_completion_context = CF_BLOCK;
#endif 
				Error err = _parse_block(func_node->body, builtins);
				if (err) {
					return err;
				}
#ifdef DEBUG_ENABLED
				keyword_completion_context = CF_GLOBAL_SPACE;
#endif 
				if (func_node->return_type != DataType::TYPE_VOID) {
					BlockNode *block = func_node->body;
					if (_find_last_flow_op_in_block(block, FlowOperation::FLOW_OP_RETURN) != OK) {
						_set_error(vformat(RTR("Expected at least one '%s' statement in a non-void function."), "return"));
						return ERR_PARSE_ERROR;
					}
				}
				current_function = StringName();
			}
		}
		tk = _get_token();
	}
#ifdef DEBUG_ENABLED
	if (check_device_limit_warnings && uniform_buffer_exceeded_line != -1) {
		_add_warning(ShaderWarning::DEVICE_LIMIT_EXCEEDED, uniform_buffer_exceeded_line, RTR("uniform buffer"), { uniform_buffer_size, max_uniform_buffer_size });
	}
#endif 
	return OK;
}
bool ShaderLanguage::has_builtin(const HashMap<StringName, ShaderLanguage::FunctionInfo> &p_functions, const StringName &p_name) {