### 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)

break;
								case ShaderNode::Varying::STAGE_FRAGMENT:
									if (current_function == varying_function_names.light) {
										var.stage = ShaderNode::Varying::STAGE_FRAGMENT_TO_LIGHT;
									}
									break;
								default:
									break;
							}
						}
						if ((var.stage != ShaderNode::Varying::STAGE_FRAGMENT && var.stage != ShaderNode::Varying::STAGE_FRAGMENT_TO_LIGHT) && var.type < TYPE_FLOAT && var.interpolation != INTERPOLATION_FLAT) {
							_set_tkpos(var.tkpos);
							_set_error(RTR("Varying with integer data type must be declared with `flat` interpolation qualifier."));
							return nullptr;
						}
					}
					if (ident_type == IDENTIFIER_FUNCTION) {
						_set_error(vformat(RTR("Can't use function as identifier: '%s'."), String(identifier)));
						return nullptr;
					}
					if (is_const) {
						last_type = IDENTIFIER_CONSTANT;
					} else {
						last_type = ident_type;
					}
					is_local = ident_type == IDENTIFIER_LOCAL_VAR || ident_type == IDENTIFIER_FUNCTION_ARGUMENT;
				}
				Node *index_expression = nullptr;
				Node *call_expression = nullptr;
				Node *assign_expression = nullptr;