Well, there is a subtle difference between the two, one should know when to use which of the two methods and this may/will come with the years of real experience as I see.
The goal remains the same but they differ in the use of techniques. Also, Design Thinking as a framework is a solution based approach which emphasises more on the Ideation part of the problem-solving.
DT also is an approach to solve wicked problems which are tough to tackle and may not have a substantial solution and is being used in solving digital user experience apart from being used in many other non-digital fields of a domain. (like finding a solution for eradicating terrorism or climate control)
Whereas UCD is a traditional and a holistic framework we follow and are accustomed to practising as UX designers. (which was also taught as a student at my design school)
I was baffled over on how design thinking can be used in the field of user experience which made me ask my UX masters at UX Mastery @HAWK as I had never used this approach:)
I found this link to be helpful:
Please correct me or add more to the thread to make the subject more meaningful.