Removed unused import [skip ci]

Author: ankane

tests/test_django.py

@@ -15,12 +15,6 @@
 from pgvector.django import VectorExtension, VectorField, HalfVectorField, BitField, SparseVectorField, IvfflatIndex, HnswIndex, L2Distance, MaxInnerProduct, CosineDistance, L1Distance, HammingDistance, JaccardDistance
 from unittest import mock
 
-try:
-    import numpy as np
-    NUMPY_AVAILABLE = True
-except ImportError:
-    NUMPY_AVAILABLE = False
-
 settings.configure(
     DATABASES={
         'default': {