Upgrade the tested up to version to WordPress 6.8 (#112)

Author: priethor

readme.txt

@@ -2,7 +2,7 @@
 Contributors: wordpressdotorg
 Tags: fields, custom fields, meta, scf
 Requires at least: 6.0
-Tested up to: 6.7
+Tested up to: 6.8
 Requires PHP: 7.4
 Stable tag: 6.4.2
 License: GPLv2 or later