Update code to support numpy >= 1.24

[smoia]

Summary

Tests in #424 were failing for python 3.10 due to some incompatibility between our code and numpy >=1.24 (see here). Versions of numpy <1.24 did not raise the same issue.
At the moment, the issue is "fixed" by declaring a required numpy version below 1.24, but a more permanent fix should be developed.

Additional detail

Next Steps

* Check failing tests with numpy 1.24 or above
* Check the reason for failure, comparing it with numpy's changelog
* Update the code to be compatible with numpy 1.24 and above