rootless-install.sh: bump up to 27.4.0

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Author: thaJeztah

rootless-install.sh

@@ -21,10 +21,10 @@ SCRIPT_COMMIT_SHA=UNKNOWN
 # This script should be run with an unprivileged user and install/setup Docker under $HOME/bin/.
 
 # latest version available in the stable channel.
-STABLE_LATEST="27.3.1"
+STABLE_LATEST="27.4.0"
 
 # latest version available in the test channel.
-TEST_LATEST="27.4.0-rc.4"
+TEST_LATEST="27.4.0"
 
 # The channel to install from:
 #   * test