build(deps): add scipy as a runtime dependency in pyproject.toml

Pip-only CI ("Unit Tests Python 3.10/3.11/3.12/3.13") was failing
with ModuleNotFoundError: No module named 'scipy' because the
surface-aware sampler now imports scipy.spatial.KDTree but scipy
was only listed in environment.yml (conda), not in pyproject.toml.

Adds scipy>=1.10 to the runtime dependencies so pip installs see
it too. The conda env was already fine.

Author: siddharth7113

pyproject.toml

@@ -13,6 +13,7 @@ requires-python = ">=3.10,<3.14"
 dependencies = [
   "numpy>=1.24",
   "pandas>=2.0",
+  "scipy>=1.10",
   "openmm>=8.0",
   "mpmath>=1.2",
 ]