php - Codeigniter 4 on Google App Engine Standard Cache unable to write to /tmp/cache/

one text

I want to deploy Codeigniter 4 to the google app engine, success deploy but after I open the site it says the error "Cache unable to write to /tmp/cache/."

i change the app/Config/Paths.php from public $writableDirectory = __DIR__ . '/../../writable'; to public $writableDirectory = '/tmp/'; because in app engine /tmp is only writeable directory but still I got error "Cache unable to write to /tmp/cache/." how can I fix it ?

I used google app engine standard environment

my app.yaml

runtime: php74

# Defaults to "serve index.php" and "serve public/index.php". Can be used to
# serve a custom PHP front controller (e.g. "serve backend/index.php") or to
# run a long-running PHP script as a worker process (e.g. "php worker.php").
#
# entrypoint: serve index.php

my composer.json

{
    "name": "codeigniter4/framework",
    "type": "project",
    "description": "The CodeIgniter framework v4",
    "homepage": "https://codeigniter.com",
    "license": "MIT",
    "require": {
        "php": "^7.3 || ^8.0",
        "ext-curl": "*",
        "ext-intl": "*",
        "ext-json": "*",
        "ext-mbstring": "*",
        "kint-php/kint": "^3.3",
        "laminas/laminas-escaper": "^2.8",
        "psr/log": "^1.1"
    },
    "require-dev": {
        "codeigniter/coding-standard": "^1.1",
        "fakerphp/faker": "^1.9",
        "friendsofphp/php-cs-fixer": "^3.1",
        "mikey179/vfsstream": "^1.6",
        "nexusphp/cs-config": "^3.3",
        "phpunit/phpunit": "^9.1",
        "predis/predis": "^1.1"
    },
    "suggest": {
        "ext-fileinfo": "Improves mime type detection for files"
    },
    "autoload": {
        "psr-4": {
            "CodeIgniter\\": "system/"
        },
        "exclude-from-classmap": [
            "**/Database/Migrations/**"
        ]
    },
    "scripts": {
        "post-update-cmd": [
            "CodeIgniter\\ComposerScripts::postUpdate"
        ],
        "test": "phpunit"
    },
    "support": {
        "forum": "http://forum.codeigniter.com/",
        "source": "https://github.com/codeigniter4/CodeIgniter4",
        "slack": "https://codeigniterchat.slack.com"
    }
}