Fix switching debug mode by explicitly setting new environment variable

ahoy.debug.yml

@@ -2,6 +2,7 @@ ahoyapi: v2
 commands:
   on:
     cmd: |
+      PHP_DEBUG=1
       echo "PHP_DEBUG=1" >>.env
       env -i $(cat .env | xargs) >.env
       composer lakedrops:docker4drupal --no-interaction
@@ -9,6 +10,7 @@ commands:
     usage: Turn on PHP debugging
   off:
     cmd: |
+      PHP_DEBUG=0
       echo "PHP_DEBUG=0" >>.env
       env -i $(cat .env | xargs) >.env
       composer lakedrops:docker4drupal --no-interaction