update lagoon from 26.1.0 to 26.4.0

Author: Su Hong

.env.default

@@ -39,7 +39,7 @@ GOVCMS_PROJECT_VERSION=3.29.1
 
 # Set the Lagoon tag to use for the upstream dockerfiles (e.g. 20.12.0)
 # See https://github.com/uselagoon/lagoon-images/releases
-LAGOON_IMAGE_VERSION=26.1.0
+LAGOON_IMAGE_VERSION=26.4.0
 
 # Set the Shipshape version to use for the upstream dockerfiles (e.g. 1.0.0-alpha.1.5.0)
 # See https://github.com/salsadigitalauorg/shipshape/releases