If you are using 1.15-s-stable (how to check), this would seem to be correct, as 1.15 is the last S (Android 12) version on offer.
Currently you could either install 1.16-t yourself, or you could wait for the /e/OS developers to finish work on the OTA upgrade from S (Android 12) to T (Android 13) via the updater (= without wiping your data, if the upgrade works out as intended), you can follow proceedings in https://community.e.foundation/tag/development-updates …
(redfin is the codename of the Pixel 5, see https://doc.e.foundation/devices)