fix: prevent vector position array from being modified (ManimCommunity#3273) (ManimCommunity#3282)

changed from np.asarray(point) to nd.array(point) in order
to make sure that a copy of the array is created even if func
is the identity function lambda pos: pos

Co-authored-by: Uwe Zimmermann <C:\Users\uwezi\AppData\Roaming\The Bat! Pwd>

Author: uwezi

manim/mobject/vector_field.py

@@ -613,7 +613,7 @@ def get_vector(self, point: np.ndarray):
             The root point of the vector.
 
         """
-        output = np.asarray(self.func(point))
+        output = np.array(self.func(point))
         norm = np.linalg.norm(output)
         if norm != 0:
             output *= self.length_func(norm) / norm