Fix for NameError in test

I was getting a NameError from the list
comprehensions saying that e.g. `pytensor_scalar`
was not defined. I'm not sure why, but this is another
(more verbose) way to do the same thing.

Author: brendan-m-murphy

tests/tensor/test_math.py

@@ -2457,11 +2457,22 @@ def pytensor_i_scalar(dtype):
         def numpy_i_scalar(dtype):
             return numpy_scalar(dtype)
 
+        pytensor_funcs = {
+            "scalar": pytensor_scalar,
+            "array": pytensor_array,
+            "i_scalar": pytensor_i_scalar,
+        }
+        numpy_funcs = {
+            "scalar": numpy_scalar,
+            "array": numpy_array,
+            "i_scalar": numpy_i_scalar,
+        }
+
         with config.change_flags(cast_policy="numpy+floatX"):
             # We will test all meaningful combinations of
             # scalar and array operations.
-            pytensor_args = [eval(f"pytensor_{c}") for c in combo]
-            numpy_args = [eval(f"numpy_{c}") for c in combo]
+            pytensor_args = [pytensor_funcs[c] for c in combo]
+            numpy_args = [numpy_funcs[c] for c in combo]
             pytensor_arg_1 = pytensor_args[0](a_type)
             pytensor_arg_2 = pytensor_args[1](b_type)
             pytensor_dtype = op(