Bump minimum requirement on XP core to 10.8.0, remove compatibility code

Author: thekid

composer.json

@@ -6,7 +6,7 @@
   "description" : "Reflection",
   "keywords": ["module", "xp"],
   "require" : {
-    "xp-framework/core": "^10.6",
+    "xp-framework/core": "^10.8",
     "xp-framework/ast": "^7.0",
     "php" : ">=7.0.0"
   },

src/main/php/lang/reflection/Type.class.php

@@ -10,11 +10,6 @@
 class Type {
   private $reflect;
   private $annotations= null;
-  private static $ENUMS;
-
-  static function __static() {
-    self::$ENUMS= interface_exists(\UnitEnum::class, false);
-  }
 
   /** @param ReflectionClass $reflect */
   public function __construct($reflect) {
@@ -58,7 +53,7 @@ public function kind(): Kind {
       return Kind::$INTERFACE;
     } else if ($this->reflect->isTrait()) {
       return Kind::$TRAIT;
-    } else if ($this->reflect->isSubclassOf(Enum::class) || (self::$ENUMS && $this->reflect->isSubclassOf(\UnitEnum::class))) {
+    } else if ($this->reflect->isSubclassOf(Enum::class) || $this->reflect->isSubclassOf(\UnitEnum::class)) {
       return Kind::$ENUM;
     } else {
       return Kind::$CLASS;