Update PHP image version to 8.4 in docker-compose.yml. (#318)

Author: terabytesoftw

docker-compose.yml

@@ -1,7 +1,6 @@
-version: '2'
 services:
   php:
-    image: yiisoftware/yii2-php:7.4-apache
+    image: yiisoftware/yii2-php:8.4-apache
     volumes:
       - ~/.composer-docker/cache:/root/.composer/cache:delegated
       - ./:/app:delegated