manifests: align default to #1113 (#1137)

Signed-off-by: Matteo Mortari <[email protected]>

Author: tarilabs

manifests/kustomize/overlays/db/model-registry-db-deployment.yaml

@@ -24,7 +24,7 @@ spec:
         runAsNonRoot: true
       containers:
       - name: db-container
-        image: mysql
+        image: mysql:8.3.0
         args:
         - --datadir
         - /var/lib/mysql/datadir