### 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)

uint64_t max_uniform_buffer_size = 0;
	int uniform_buffer_exceeded_line = -1;
	bool check_device_limit_warnings = false;
	{
		RenderingDevice *device = RenderingDevice::get_singleton();
		if (device != nullptr) {
			check_device_limit_warnings = check_warnings && HAS_WARNING(ShaderWarning::DEVICE_LIMIT_EXCEEDED_FLAG);
			max_uniform_buffer_size = device->limit_get(RenderingDevice::LIMIT_MAX_UNIFORM_BUFFER_SIZE);
		}
	}
#endif 
	ShaderNode::Uniform::Scope uniform_scope = ShaderNode::Uniform::SCOPE_LOCAL;
	stages = &p_functions;
	const FunctionInfo &constants = p_functions.has("constants") ? p_functions["constants"] : FunctionInfo();
	HashMap<String, String> defined_modes;
	while (tk.type != TK_EOF) {
		switch (tk.type) {
			case TK_RENDER_MODE: {
				while (true) {
					StringName mode;
					_get_completable_identifier(nullptr, COMPLETION_RENDER_MODE, mode);
					if (mode == StringName()) {
						_set_error(RTR("Expected an identifier for render mode."));
						return ERR_PARSE_ERROR;
					}
					const String smode = String(mode);
					if (shader->render_modes.has(mode)) {
						_set_error(vformat(RTR("Duplicated render mode: '%s'."), smode));
						return ERR_PARSE_ERROR;
					}