Add pyxtal to tests

[jan-janssen]

No description provided.

[jan-janssen]

The following packages are incompatible
├─ numpy 1.26.0**  is installable with the potential options
│  ├─ numpy 1.26.0, which can be installed;
│  ├─ numpy 1.26.0 would require
│  │  └─ python >=3.10,<3.11.0a0 , which can be installed;
│  ├─ numpy 1.26.0 would require
│  │  └─ python >=3.12.0rc3,<3.13.0a0  with the potential options
│  │     ├─ python 3.12.0, which can be installed;
│  │     └─ python 3.12.0rc3 would require
│  │        └─ _python_rc  , which does not exist (perhaps a missing channel);
│  └─ numpy 1.26.0 would require
│     └─ python >=3.9,<3.10.0a0 , which can be installed;
└─ pyxtal 0.6.0**  is installable and it requires
   └─ numba >=0.55.2  with the potential options
      ├─ numba [0.55.2|0.56.2|...|0.57.1] would require
      │  └─ python >=3.10,<3.11.0a0 , which can be installed;
      ├─ numba [0.55.2|0.56.2|0.56.3] would require
      │  └─ python >=3.7,<3.8.0a0 , which can be installed;
      ├─ numba [0.55.2|0.56.2|...|0.57.1] would require
      │  └─ python >=3.8,<3.9.0a0 , which can be installed;
      ├─ numba [0.55.2|0.56.2|...|0.57.1] would require
      │  └─ python >=3.9,<3.10.0a0 , which can be installed;
      ├─ numba [0.57.0|0.57.1] would require
      │  └─ numpy >=1.21,!=1.22.0,!=1.22.1,!=1.22.2,<1.25 , which conflicts with any installable versions previously reported;
      └─ numba [0.56.3|0.56.4|0.57.0|0.57.1] conflicts with any installable versions previously reported.

[jan-janssen]

This was done in #100