TASK: Define compatibility with PHP 8 and Flow 8

Author: Sebastian Helzle

composer.json

@@ -6,9 +6,9 @@
         "bin-dir": "bin"
     },
     "require": {
-        "neos/flow": "^7.0",
+        "neos/flow": "^7.0 || ^8.0 || dev-master",
         "t3n/graphql": "^3.0",
-        "php": "^7.3",
+        "php": ">=7.3",
         "ext-json": "*"
     },
     "autoload": {