dorothy: fix ci: use /dev/stderr not /dev/tty

/ref 93490f4

commands/dorothy

@@ -1161,13 +1161,12 @@ function dorothy() (
 			esac
 		done
 
-		# prepare, without conflating stdout
+		# prepare
 		{
 			ensure_dorothy_configured
 			assert_dorothy_configured
 			ensure_minimal_dependencies
-			echo sup
-		} &>/dev/tty
+		} >/dev/stderr # don't conflate stdout, don't use /dev/tty as tty doesn't exist on CI
 
 		# run the command, inheriting our preconfigured environment
 		("${args[@]}")
@@ -1399,12 +1398,12 @@ function dorothy() (
 	# Act
 
 	# ensure the prerequisites are installed in case the user skipped them
-	ensure_prereq_dependencies &>/dev/tty # don't conflate stdout/stderr for benefit of [dorothy run]
+	ensure_prereq_dependencies >/dev/stderr # don't conflate stdout, don't use /dev/tty as tty doesn't exist on CI
 
 	# all helpers are defined, and argument overrides are handled
 	# so prepare the local environment context with what is necessary for dorothy
 	# such that the following [choose-option] will be found
-	prepare_dorothy &>/dev/tty # don't conflate stdout/stderr for benefit of [dorothy run]
+	prepare_dorothy >/dev/stderr # don't conflate stdout, don't use /dev/tty as tty doesn't exist on CI
 
 	if test "$(type -t "act_$action")" = 'function'; then
 		"act_$action" "${args[@]}"