Lower precision in TestFusion parametrization

This was not an issue in my local machine, but failed on the Github CI. It could be due to compiler optimizations. Case 69 used to look like this:

```python
 Elemwise{Composite{(i0 * tan(i0) * tan(i0) * i1)}} [id C]
 |x [id A]
 |x [id A]
 ```

 And now looks like this
 ```python
 Elemwise{Composite{(i0 * tan(i0) * tan(i0) * i0)}} [id C]
 |x [id A] [None]
 ```

Author: ricardoV94

tests/tensor/rewriting/test_elemwise.py

@@ -882,6 +882,7 @@ def my_init(dtype="float64", num=0):
                 1,
                 fxv * np.tan(fxv) * np.tan(fxv) * fxv,
                 "float32",
+                1e-5,
             ),
             (
                 mul(ftanx, ftanx, fx + fy),
@@ -890,6 +891,7 @@ def my_init(dtype="float64", num=0):
                 1,
                 np.tan(fxv) * np.tan(fxv) * (fxv + fyv),
                 "float32",
+                1e-5,
             ),  # 70
             # Cases with different broadcast pattern. They should not
             # be merged as this would duplicate computation
@@ -973,7 +975,11 @@ def my_init(dtype="float64", num=0):
     def test_elemwise_fusion(self, case, nb_repeat=1, assert_len_topo=True):
         """Verify that `Elemwise` fusion works."""
 
-        g, sym_inputs, val_inputs, nb_elemwise, answer, out_dtype = case
+        if len(case) == 6:
+            g, sym_inputs, val_inputs, nb_elemwise, answer, out_dtype = case
+            atol = None
+        else:
+            g, sym_inputs, val_inputs, nb_elemwise, answer, out_dtype, atol = case
 
         if isinstance(out_dtype, dict):
             out_dtype = out_dtype[config.cast_policy]
@@ -1000,9 +1006,10 @@ def test_elemwise_fusion(self, case, nb_repeat=1, assert_len_topo=True):
                 f(*val_inputs)
             out = [o.get_value() for o in out]
 
-        atol = 1e-8
-        if any(o == "float32" for o in out_dtype):
-            atol = 1e-6
+        if atol is None:
+            atol = 1e-8
+            if any(o == "float32" for o in out_dtype):
+                atol = 1e-6
 
         for o, a in zip(out, answer):
             np.testing.assert_allclose(o, a * nb_repeat, atol=atol)