Fix remaining Copilot review issues: unused import and duplicate assertion

- test_abstract.py: remove unused `import numpy as np`; fix duplicate
  assertion so second check covers row [1, :] not [0, :] again
- test_fit_imaging.py: remove unused fixtures and dead setup block from
  covariance test (only masked_imaging_covariance_7x7 is needed)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: 2 people

test_autolens/imaging/test_fit_imaging.py

@@ -549,16 +549,8 @@ def test__figure_of_merit__sub_2_oversampling__linear_operated_profiles__inversi
 
 
 def test__figure_of_merit__sub_2_oversampling__covariance_noise_matrix__expected_log_likelihood(
-    masked_imaging_covariance_7x7, image_7x7, psf_3x3, noise_map_7x7, mask_2d_7x7
+    masked_imaging_covariance_7x7,
 ):
-    dataset = al.Imaging(
-        data=image_7x7,
-        psf=psf_3x3,
-        noise_map=noise_map_7x7,
-        over_sample_size_lp=2,
-    )
-    masked_imaging_7x7 = dataset.apply_mask(mask=mask_2d_7x7)
-
     g0 = al.Galaxy(
         redshift=0.5,
         bulge=al.lp.Sersic(centre=(0.05, 0.05), intensity=1.0),

test_autolens/point/fit/positions/image/test_abstract.py

@@ -1,4 +1,3 @@
-import numpy as np
 import pytest
 
 import autolens as al
@@ -41,6 +40,6 @@ def test__abstract_fit_positions_image_pair__multi_plane_tracer__model_positions
     assert fit_0.model_data[0, :] == pytest.approx(
         scaling_factor * fit_1.model_data.array[0, :], 1.0e-1
     )
-    assert fit_0.model_data[0, :] == pytest.approx(
-        scaling_factor * fit_1.model_data.array[0, :], 1.0e-1
+    assert fit_0.model_data[1, :] == pytest.approx(
+        scaling_factor * fit_1.model_data.array[1, :], 1.0e-1
     )