bump spanner emulator to match version used in spicedb

Author: ecordell

e2e/databases/manifests/spanner.yaml

@@ -35,7 +35,7 @@ spec:
     spec:
       containers:
         - name: spanner
-          image: gcr.io/cloud-spanner-emulator/emulator:1.5.4
+          image: gcr.io/cloud-spanner-emulator/emulator:1.5.14
           imagePullPolicy: IfNotPresent
           ports:
             - containerPort: 9010