### 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)

tk = _get_token();
					}
					arg.array_size = arg_array_size;
					func_node->arguments.push_back(arg);
					if (tk.type == TK_COMMA) {
						tk = _get_token();
						
					} else if (tk.type != TK_PARENTHESIS_CLOSE) {
						_set_expected_error(",", ")");
						return ERR_PARSE_ERROR;
					}
				}
				if (p_functions.has(name)) {
					
					if (func_node->arguments.size() > 0) {
						_set_error(vformat(RTR("Function '%s' expects no arguments."), String(name)));
						return ERR_PARSE_ERROR;
					}
					if (func_node->return_type != TYPE_VOID) {
						_set_error(vformat(RTR("Function '%s' must be of '%s' return type."), String(name), "void"));
						return ERR_PARSE_ERROR;
					}
				}
				
				tk = _get_token();
				if (tk.type != TK_CURLY_BRACKET_OPEN) {
					_set_error(RTR("Expected a '{' to begin function."));
					return ERR_PARSE_ERROR;
				}
				current_function = name;