feat(math): support erfinv on mlx (#19628)

Author: lpizzinidev

keras/src/backend/mlx/math.py

@@ -102,6 +102,11 @@ def erf(x):
     return mx.erf(x)
 
 
+def erfinv(x):
+    x = convert_to_tensor(x)
+    return mx.erfinv(x)
+
+
 def solve(a, b):
     raise NotImplementedError(
         "Linear system solving not yet implemented in mlx"

keras/src/backend/mlx/trainer.py

@@ -3,7 +3,6 @@
 
 from keras.src import backend
 from keras.src import callbacks as callbacks_module
-from keras.src import ops
 from keras.src import optimizers as optimizers_module
 from keras.src import tree
 from keras.src.backend.common import standardize_dtype