Errors using Group By node on MacOS 15.4

After the last MacOS update, Orange started throwing more errors with 'Group By' node, and the data doesn't flow through the node to the rest of the workflow.

**What's wrong?**

**How can we reproduce the problem?**

**What's your environment?**

- Operating system:
- Orange version:
- How you installed Orange:

No source file, test, Orange version, installation method, workflow, data, or complete error details are provided. Start by collecting those details and reproducing the Group By node failure on macOS 15.4; done means data reaches downstream nodes reliably, with a regression test covering the failure.

Written by the indexing model from the issue text.