feat(phpunit): require dev

composer.json

@@ -36,7 +36,7 @@
         ]
     },
     "archive": {
-        "exclude": ["node_modules","/archives","/*.zip","/*.gz","/*.bz2"]
+        "exclude": ["node_modules","/archives","/*.zip","/*.gz","/*.bz2","vendor/seacms/*/tests/","vendor/picocms/plugins/*/tests/"]
     },
     "repositories": {
         "picocms/pico": {
@@ -67,5 +67,8 @@
             "type": "vcs",
             "url": "https://git.defis.info/SeaCMS/seacms-theme"
         }
+    },
+    "require-dev": {
+        "phpunit/phpunit": "^9.6"
     }
 }