Add PHP build version arg to test service

This should fix BuildKit error due to "unrecognized format"

Author: XedinUnknown

docker-compose.yml

@@ -70,6 +70,7 @@ services:
       target: build
       args:
         PHP_BUILD_VERSION: $PHP_BUILD_VERSION
+        PHP_TEST_VERSION: $PHP_TEST_VERSION
         WORDPRESS_VERSION: $WORDPRESS_VERSION
         BUILD_ROOT_PATH: $BUILD_ROOT_PATH
     container_name: "${PROJECT_NAME}_build"