I don't think it's possible to filter articles by topic with a single query in the API. However, you can use Wikidata to detect and filter politics, celebrities and so. You'll need to follow several steps:
- Get articles from the query you gave in the question.
- Query English language Wikipedia to get Wikidata item for each article.
- Query Wikidata to get statements about the item.
- Decide if you want the article to be included depending on the statements you got.
There are different tools for each step, but the most critical one is step 4. You'll lucky if most politicians have occupation:politician but there will likely be several occupation tags for celebrities.
Using categories from Wikipedia is another option but I won't advise to take it due to the structure of categories - a category of actors can have subcategories with actors along with subcategories with films, for example.