[server] Fix spicedb retry on DEADLINE_EXCEEDED & UNAVAILABLE

Author: geropl

components/server/src/authorization/spicedb-authorizer.ts

@@ -189,7 +189,7 @@ export class SpiceDBAuthorizer {
             try {
                 const checkClient = attempt > 1; // the last client error'd out, so check if we should get a new one
                 const client = this.clientProvider.getClient(checkClient);
-                return code(client);
+                return await code(client);
             } catch (err) {
                 // Check: Is this a "no connection to upstream" error? If yes, retry here, to work around grpc/grpc-js bugs introducing high latency for re-tries
                 if (