chore: don't use pipe operator, not supported on 3.9

freqtrade/util/rich_progress.py

@@ -1,3 +1,5 @@
+from typing import Union
+
 from rich.console import ConsoleRenderable, Group, RichCast
 from rich.progress import Progress
 
@@ -7,6 +9,6 @@ class CustomProgress(Progress):
         self._cust_objs = cust_objs
         super().__init__(*args, **kwargs)
 
-    def get_renderable(self) -> ConsoleRenderable | RichCast | str:
+    def get_renderable(self) -> Union[ConsoleRenderable, RichCast, str]:
         renderable = Group(*self._cust_objs, *self.get_renderables())
         return renderable