[lldb][Python] Fix SBProcessInfoList subscript and iterator (#214038) Found this in #214000 when looking through the generated `__init__.py`. [`SBProcessInfo::GetProcessInfoAtIndex`](https://lldb.llvm.org/python_api/lldb.SBProcessInfoList.html#lldb.SBProcessInfoList.GetProcessInfoAtIndex) takes a reference to an info that it fills instead of returning one. So we need to pass that `ProcessInfo` to it. GitOrigin-RevId: 9fbe25d98ff36d5820e8b15981e9950b40ad3f49