fix: load env groups on create crashing (#3826)

Co-authored-by: David Townley <davidtownley@Davids-MacBook-Air.local>
Co-authored-by: Ian Edwards <ianedwards559@gmail.com>

dashboard/src/main/home/app-dashboard/validate-apply/app-settings/EnvGroupModal.tsx

@@ -31,7 +31,7 @@ const EnvGroupModal: React.FC<Props> = ({ append, setOpen, baseEnvGroups }) => {
   ] = useState<PopulatedEnvGroup | null>(null);
 
   const { watch } = useFormContext<PorterAppFormData>();
-  const envGroups = watch("app.envGroups");
+  const envGroups = watch("app.envGroups", []);
 
   const onSubmit = useCallback(() => {
     if (selectedEnvGroup) {