Fix scipy v0.18 issues

[gtrevisan]

scipy v1.18, probably in the scipy.interpolate functions, breaks our tests for C-MOD.

uv add 'scipy>=1.18'
uv run pytest
uv run pytest tests/test_against_cache.py -k '[dipprog_dt]'

reference:

• https://docs.scipy.org/doc/scipy/release/1.18.0-notes.html