Fix a potential NPE (#8975)

* Fix a potential NPE

* GCA suggestion

Author: joehan

src/deploy/dataconnect/prepare.ts

@@ -69,7 +69,7 @@ export default async function (context: any, options: DeployOptions): Promise<vo
       await diffSchema(
         options,
         si.schema,
-        si.dataConnectYaml.schema.datasource.postgresql?.schemaValidation,
+        si.dataConnectYaml.schema?.datasource?.postgresql?.schemaValidation,
       );
     }
     utils.logLabeledBullet("dataconnect", "Checking for CloudSQL resources...");

src/deploy/dataconnect/release.ts

@@ -38,7 +38,7 @@ export default async function (
     })
     .map((s) => ({
       schema: s.schema,
-      validationMode: s.dataConnectYaml.schema.datasource.postgresql?.schemaValidation,
+      validationMode: s.dataConnectYaml?.schema?.datasource?.postgresql?.schemaValidation,
     }));
 
   if (wantSchemas.length) {