Preserve .vscode-shared.

The latest vscode is storing data in ~/.vscode-shared that contains the "Open Recent" entries and the settings on which folders are trusted.

nix/configuration/roles/vscode/default.nix

@@ -121,6 +121,12 @@ in
             group = "talexander";
             mode = "0755";
           }
+          {
+            directory = ".vscode-shared";
+            user = "talexander";
+            group = "talexander";
+            mode = "0755";
+          }
         ];
       };
     };