Fix output dtype of elementwise_div (#40890)

* fix outpu dtype of elementwise_div

* fix ci

* fix ci

python/paddle/fluid/dygraph/math_op_patch.py

@@ -264,6 +264,10 @@ def monkey_patch_math_varbase():
                 self = other_var
                 other_var = tmp
 
+            if op_type == 'elementwise_div' and self.dtype in _supported_int_dtype_:
+                self = astype(self, 'float32')
+                other_var = astype(other_var, 'float32')
+
             # 4. calculation
             axis = -1
             math_op = getattr(_C_ops, op_type)