Relax dependency to support NumPy 2.0 and later

This package is not affected by the breaking changes in NumPy 2.0.

When running all of the tests cases with NumPy 2.0.0rc1, the image
"doc/getting-started/lorenz63_forecast_regularised.png" was slightly
different; the y-axis line extended one pixel higher than previously,
and several surrounding pixels differ slightly (due to antialiasing).
The modified image is not included in this commit.

pyproject.toml

@@ -27,7 +27,7 @@ classifiers = [
 dependencies = [
   "h5py ~= 3.0",
   "lhs ~= 0.4",
-  "numpy ~= 1.17",
+  "numpy >= 1.17",
   "packaging ~= 21.3",
   "scipy ~= 1.4",
   "tomli ~= 2.0",