What globbing pattern should be used to recursively find all sass files except those in a directory?

Question

Regular Expressions

The frontend directory structure is as follows:

.
├── app
│   ├── js
│   ├── pug
│   ├── sass
│   │   ├── vendor
│   │   │   ├── bootstrap.scss
│   │   │   └── font-awesome.scss
│   │   └── main.scss

During the build of the project, it is necessary to separately process custom sass files and sass files of third-party libraries located in the sass/vendor/ directory . In both cases, I want to achieve support for recursive processing (so that the nesting of directories can be any).
An unsuccessful attempt was made to apply the following pattern:
app/sass/!(vendor)/**/*.+(scss|sass)
Where did I go wrong?