Update readme.

Author: ndiego

readme.txt

@@ -3,7 +3,7 @@ Author URI:        https://www.nickdiego.com/?bv_query=readme
 Contributors:      ndiego, outermostdesign
 Tags:              visibility, dynamic content, conditional content, conditional blocks, restrict blocks
 Requires at least: 6.2
-Tested up to:      6.3
+Tested up to:      6.4
 Requires PHP:      7.4
 Stable tag:        3.2.0
 License:           GPL-2.0