Failing `checkCommitMessages` fuzz test

**Describe the bug**
An interesting bug popped up during one of the CI executions:

<img width="1660" height="1261" alt="Image" src="https://github.com/user-attachments/assets/557f7409-ae63-4939-a327-0b32930a94aa" />

Apparently, using the commit message `{"toString": ""}` makes the function behave unexpectedly/error out.