Change commit message for DiffTrain commigs (#26203)

Previously, the commit message looked something like this in Github: 
<img width="921" alt="Screenshot 2023-02-20 at 13 52 35"
src="https://user-images.githubusercontent.com/1733610/220126265-d77931e0-18ac-46a0-bf23-d868f8af17a9.png">

With this change, it will look like:

DiffTrain build for commit db5e6250d4bbb70c5085c58694a2e9c78c3f6371.