Change min supported DS SDK version for Java (#5628)

Remove `beta` as `6.5.0` has been released.

Author: adinauer

src/includes/sampling-supported-sdks.mdx

@@ -6,5 +6,5 @@
 - Dart and Flutter: 6.11.0 or later
 - PHP: 3.9.0 or later
 - Ruby: 5.5.0 or later
-- Java: 6.5.0-beta.2 or later
+- Java: 6.5.0 or later
 - .NET: 3.22.0 or later