docs: fix release announcement link in preview page (cloudnative-pg#7571)

Signed-off-by: Marco Nenciarini <marco.nenciarini@enterprisedb.com>

Author: mnencia

docs/src/preview_version.md

@@ -33,13 +33,13 @@ may contain serious bugs. Features in preview versions may change in ways that
 are not backwards compatible and could be removed entirely.
 
 ## Current Preview Version
-
+<!--
 There are currently no preview versions available.
+-->
 
 The current preview version is **1.26.0-rc3**.
 
 For more information on the current preview version and how to test, please view the links below:
 
-- [Announcement](https://cloudnative-pg.io/releases/cloudnative-pg-1-26.0-rc2-released/)
+- [Announcement](https://cloudnative-pg.io/releases/cloudnative-pg-1-26.0-rc3-released/)
 - [Documentation](https://cloudnative-pg.io/documentation/preview/)
-