Suppress numpy warning in WakePotential

Suppress numpy warning for floating-point operations in the WakePotential class.

mbtrack2/tracking/wakepotential.py

@@ -77,6 +77,9 @@ class WakePotential(Element):
         self.ring = ring
         self.n_bin = n_bin
         self.check_sampling()
+        
+        # Suppress numpy warning for floating-point operations.
+        np.seterr(invalid='ignore')
             
     def charge_density(self, bunch):
         """