DOC: remove concat dict sortedness statement (pandas-dev#58518)

* DOC: remove concat dict sortedness statement

* DOC: simplify objs order comment

Author: er-eis

pandas/core/reshape/concat.py

@@ -171,7 +171,7 @@ def concat(
     Parameters
     ----------
     objs : an iterable or mapping of Series or DataFrame objects
-        If a mapping is passed, the sorted keys will be used as the `keys`
+        If a mapping is passed, the keys will be used as the `keys`
         argument, unless it is passed, in which case the values will be
         selected (see below). Any None objects will be dropped silently unless
         they are all None in which case a ValueError will be raised.