Dispatch numpy ufuncs for expr functions

Replace per-function PyNumber_Check lambdas with a unified _dispatch_ufunc helper that vectorizes conversion of Python numbers to Constant via _to_const and np.frompyfunc. Removed the direct cimport of PyNumber_Check and updated exp/log/sqrt/sin/cos to call _dispatch_ufunc. _dispatch_ufunc also coerces ndarray results to MatrixExpr, centralizing numpy ufunc handling and improving array support for expression construction.

Author: Zeroto521

src/pyscipopt/expr.pxi

@@ -48,7 +48,6 @@ from typing import TYPE_CHECKING, Literal
 import numpy as np
 
 from cpython.dict cimport PyDict_Next, PyDict_GetItem
-from cpython.number cimport PyNumber_Check
 from cpython.object cimport Py_TYPE
 from cpython.ref cimport PyObject
 from cpython.tuple cimport PyTuple_GET_ITEM
@@ -857,11 +856,21 @@ cdef class Constant(GenExpr):
         return self.number
 
 
-exp = lambda x: Constant(x) if PyNumber_Check(x) else np.exp(x)
-log = lambda x: Constant(x) if PyNumber_Check(x) else np.log(x)
-sqrt = lambda x: Constant(x) if PyNumber_Check(x) else np.sqrt(x)
-sin = lambda x: Constant(x) if PyNumber_Check(x) else np.sin(x)
-cos = lambda x: Constant(x) if PyNumber_Check(x) else np.cos(x)
+exp = lambda x: _dispatch_ufunc(x, np.exp)
+log = lambda x: _dispatch_ufunc(x, np.log)
+log = lambda x: _dispatch_ufunc(x, np.log)
+sqrt = lambda x: _dispatch_ufunc(x, np.sqrt)
+sin = lambda x: _dispatch_ufunc(x, np.sin)
+cos = lambda x: _dispatch_ufunc(x, np.cos)
+
+cdef inline object _to_const(object x):
+    return Constant(<double>x) if _is_number(x) else x
+
+cdef object _vec_const = np.frompyfunc(_to_const, 1, 1)
+
+cdef inline object _dispatch_ufunc(object x, object ufunc):
+    res = ufunc(_vec_const(x))
+    return res.view(MatrixExpr) if isinstance(res, np.ndarray) else res
 
 
 def expr_to_nodes(expr):