Fix segmentation fault

This fixes a segmentation fault in the MAXCUT solvers. (Sorry I let that stand for so long without noticing it!)

Full Changelog: v9.5.11...v9.5.12

sha1sum results:
650b2aae6367b95bbf266ee8dbdcf4d916978973 pyqrackising-9.5.12-py3-none-macosx_14_0_arm64.whl
5ec97644e0bb628b128d258e88ecae69d46eaf84 pyqrackising-9.5.12-py3-none-macosx_15_0_arm64.whl
b5f034e6768d31c535a49e98dfb34122affe857b pyqrackising-9.5.12-py3-none-manylinux_2_35_x86_64.whl
38e76d6adae6507b8efe259dd834648b02b506ed pyqrackising-9.5.12-py3-none-manylinux_2_39_x86_64.whl
907caf08c5c97609359bcfb261b812d08ab03f41 pyqrackising-9.5.12-py3-none-win_amd64.whl
121f47da3b97dc11e899c258371d445d500906a2 pyqrackising-9.5.12.tar.gz