I try to stay away from these people, and while writing this post I realized that all of my closest friends rarely gossip.
I also noticed those kind of people in a work context are both a treasure and a peril. They are a treasure because they tend to give information for free, but they are also liabilities as these kind of people won't move far the social/corporate ladder.
People who give informations for free do not understand the value of information in the first place.
The second way I judge character is by checking how late they are at appointments, meetings, parties, video calls, whatever. People that are often late simply value their own time more than yours, they disrespect you.