doc: fix changelog for v10.8.0

Add missing link at the top.

PR-URL: #22072
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Vse Mozhet Byt <vsemozhetbyt@gmail.com>
Reviewed-By: Jon Moss <me@jonathanmoss.me>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

Author: targos

doc/changelogs/CHANGELOG_V10.md

@@ -9,6 +9,7 @@
 </tr>
 <tr>
 <td>
+<a href="#10.8.0">10.8.0</a><br/>
 <a href="#10.7.0">10.7.0</a><br/>
 <a href="#10.6.0">10.6.0</a><br/>
 <a href="#10.5.0">10.5.0</a><br/>