`sys.exit` from Python no longer exits the GDB process

[Gulshan Singh via Gdb <gdb@sourceware.org>]

I'm using GNU gdb (Ubuntu 15.0.50.20240403-0ubuntu1)
15.0.50.20240403-git on Ubuntu 24.04, and I'm observing different
behavior with `sys.exit` in Python then when I was using GNU gdb
(Ubuntu 12.1-0ubuntu1~22.04.2) 12.1 on Ubuntu 22.04.

In GDB 12.1, `sys.exit(1)` in Python would exit the GDB process with
an exit code of 1. In GDB 15.0, I'm seeing that there's an exception
message instead, and GDB does not exit:
```
Python Exception <class 'SystemExit'>: 1
Error occurred in Python: 1
```

Is this a bug or intentional behavior? I work on an open source Python
GDB plugin that has some unit tests that get run inside GDB. When an
exception occurs, it's caught and we exit with `sys.exit` so we can
check the return code from our test running scripts. But with the
latest GDB this no longer happens, eventually we run the `quit`
command, and the exit code is zero. If this is intended behavior, is
there any alternative we can use to quit GDB with a non-zero exit code
from Python?