dirstate-v2: Remove the `.d` suffix in data file names

dirstate-v2: Remove the `.d` suffix in data file names

It could cause confusion since `.d` is already used for revlogs.
This suffix is not necessary since there is already a `dirstate.` prefix.

Differential Revision: https://phab.mercurial-scm.org/D11413

--- a/mercurial/dirstateutils/docket.py	Mon Sep 13 18:48:48 2021 +0200
+++ b/mercurial/dirstateutils/docket.py	Mon Jul 26 10:26:45 2021 +0200
@@ -34,7 +34,7 @@
 
 
 class DirstateDocket(object):
-    data_filename_pattern = b'dirstate.%s.d'
+    data_filename_pattern = b'dirstate.%s'
 
     def __init__(self, parents, data_size, tree_metadata, uuid):
         self.parents = parents

--- a/rust/hg-core/src/dirstate_tree/on_disk.rs	Mon Sep 13 18:48:48 2021 +0200
+++ b/rust/hg-core/src/dirstate_tree/on_disk.rs	Mon Jul 26 10:26:45 2021 +0200
@@ -265,7 +265,7 @@
     }
 
     pub fn data_filename(&self) -> String {
-        String::from_utf8(format_bytes!(b"dirstate.{}.d", self.uuid)).unwrap()
+        String::from_utf8(format_bytes!(b"dirstate.{}", self.uuid)).unwrap()
     }
 }