### 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)

p_block->block_tag = SubClassTag::TAG_GLOBAL;
						}
						if (!mn->call_expression) {
							return nullptr;
						}
					} else if (tk.type == TK_BRACKET_OPEN) {
						Node *index_expression = _parse_and_reduce_expression(p_block, p_function_info);
						if (!index_expression) {
							return nullptr;
						}
						if (index_expression->get_array_size() != 0 || (index_expression->get_datatype() != TYPE_INT && index_expression->get_datatype() != TYPE_UINT)) {
							_set_error(RTR("Only integer expressions are allowed for indexing."));
							return nullptr;
						}
						if (index_expression->type == Node::TYPE_CONSTANT) {
							ConstantNode *cnode = static_cast<ConstantNode *>(index_expression);
							if (cnode) {
								if (!cnode->values.is_empty()) {
									int value = cnode->values[0].sint;
									if (value < 0 || value >= array_size) {
										_set_error(vformat(RTR("Index [%d] out of range [%d..%d]."), value, 0, array_size - 1));
										return nullptr;
									}
								}
							}
						}
						tk = _get_token();
						if (tk.type != TK_BRACKET_CLOSE) {
							_set_expected_error("]");
							return nullptr;