### 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)

}
						}
					}
					if (n->type == Node::TYPE_CONSTANT) {
						ConstantNode *const_node = static_cast<ConstantNode *>(n);
						if (const_node && const_node->values.size() == 1) {
							var.value = const_node->values[0];
						}
					}
					if (!_compare_datatypes(var.type, var.struct_name, var.array_size, n->get_datatype(), n->get_datatype_name(), n->get_array_size())) {
						return ERR_PARSE_ERROR;
					}
					decl.initializer.push_back(n);
					tk = _get_token();
				} else {
					if (is_const) {
						_set_error(RTR("Expected initialization of constant."));
						return ERR_PARSE_ERROR;
					}
				}
				vdnode->declarations.push_back(decl);
				p_block->variables[name] = var;
				if (!fixed_array_size) {
					array_size = 0;
				}
				if (tk.type == TK_SEMICOLON) {
					break;
				} else if (tk.type != TK_COMMA) {
					_set_expected_error(",", ";");
					return ERR_PARSE_ERROR;