[DOC-13425]: Update the tools download link for 7.6.8 (#3856)

Author: RayOffiah

modules/cli/pages/cli-intro.adoc

@@ -1,6 +1,6 @@
 = CLI Reference
 :description: The command-line interface (CLI) tools let you manage and monitor your Couchbase Server installation including clusters, servers, vBuckets, and XDCR.
-:tools-ver: 7.6.6
+:tools-ver: 7.6.8
 
 [abstract]
 {description}