diff -r d3eb5f50052c -r bf8837e3d7ce mercurial/configitems.py
--- a/mercurial/configitems.py	Tue Sep 28 20:00:19 2021 +0200
+++ b/mercurial/configitems.py	Mon Sep 27 12:09:15 2021 +0200
@@ -964,11 +964,6 @@
 )
 coreconfigitem(
     b'experimental',
-    b'dirstate-tree.in-memory',
-    default=False,
-)
-coreconfigitem(
-    b'experimental',
     b'editortmpinhg',
     default=False,
 )