Prefer PHP 8 attributes over xp::$meta

[thekid]

This PR always uses the native syntax instead of using the information available in xp::$meta in PHP 8.

Runtime version	Source
PHP 7.*	Meta information if available, syntax tree otherwise
PHP 8.* (before)	Meta information if available, PHP 8 attributes reflection otherwise
PHP 8.* (after this PR is merged)	PHP 8 attributes reflection only 🆕

Changes to the compiler

Here's what we could do in XP Compiler:

diff --git a/src/main/php/lang/ast/emit/php/XpMeta.class.php b/src/main/php/lang/ast/emit/php/XpMeta.class.php
index 0da5bcc..444e052 100755
--- a/src/main/php/lang/ast/emit/php/XpMeta.class.php
+++ b/src/main/php/lang/ast/emit/php/XpMeta.class.php
@@ -96,12 +96,4 @@ trait XpMeta {
   protected function emitComment($result, $comment) {
     // Omit from generated code
   }
-
-  protected function emitAnnotation($result, $annotation) {
-    // Omit from generated code
-  }
-
-  protected function emitAnnotations($result, $annotations) {
-    // Omit from generated code
-  }
 }

However, this would require changes to XP Core to parse annotations from the source code even if meta information is available - thus we'll have to wait for xp-framework/rfc#338