fix `np.int` was a deprecated alias for the builtin `int` (numpy)

heat/utils.py

@@ -45,7 +45,7 @@ def getTemp(solver, linelabel="Bottom", sort='x'):
     import numpy as np
     v = np.array(extr.execute())
     
-    nos = np.zeros_like(v, dtype=np.int)
+    nos = np.zeros_like(v, dtype=int)
     nxs = np.zeros_like(v)
     nys = np.zeros_like(v)
     for i in range(len(v)):