Bump tested up to header to indicate WordPress 6.9 support.

Author: peterwilsoncc

readme.txt

@@ -1,7 +1,7 @@
 === Publisher Media Kit ===
 Contributors:      10up, jeffpaul, faisal03
 Tags:              media kit, audience profiles, digital ad specs, ad rates
-Tested up to:      6.8
+Tested up to:      6.9
 Stable tag:        1.3.6
 License:           GPLv2 or later
 License URI:       https://www.gnu.org/licenses/gpl-2.0.html