Segfault on in-place difference

The following produces a segfault for me on Ubuntu 23.10 with Python 3.10.13 and `roaringbitmap` 0.7.2:
```python
import random
import roaringbitmap


random.seed(232992)

set_a = roaringbitmap.RoaringBitmap(random.sample(range(235342), k=169308))
set_b = roaringbitmap.RoaringBitmap(random.sample(range(255999), k=255713))
set_a -= set_b
```
