Fix pytest9 and numpy2 deprecations

[taranarmo]

Code PR

• I have read through the contributing notes and understand the structure of the package. In particular, if my PR modifies code of plotly.graph_objects, my modifications concern the code generator and not the generated files.
• I have added tests or modified existing tests.
• For a new feature, I have added documentation examples (please see the doc checklist as well).
• I have added a CHANGELOG entry if changing anything substantial.
• For a new feature or a change in behavior, I have updated the relevant docstrings in the code.

This PR fixes tests compatibility with pytest9 and numpy2
Found during nixpkgs build failure investigation NixOS/nixpkgs#493605

[taranarmo]

test fail seems to be unrelated to the change

[thunze]

There are existing open PRs for (roughly) all of these changes: #5522, #5521, #5505

[taranarmo]

There are existing open PRs for (roughly) all of these changes: #5522, #5521, #5505

for some reason I didn't find them :/