[Bug]: Not possible to update apps via web interface if config is read only

⚠️ This issue respects the following points: ⚠️

• This is a bug, not a question or a configuration/webserver/proxy issue.
• This issue is not already reported on Github OR Nextcloud Community Forum (I've searched it).
• Nextcloud Server is up to date. See Maintenance and Release Schedule for supported versions.
• I agree to follow Nextcloud's Code of Conduct.

Bug description

Not possible to update apps via web interface if config is read only

Steps to reproduce

1. Set "config_is_read_only": true in config.php
2. Try to update app via web interface
3. Error is shown:
   
   

Expected behavior

It should update the app

Installation method

None

Nextcloud Server version

29

Operating system

Other

PHP engine version

PHP 8.2

Web server

Nginx

Database engine version

PostgreSQL

Is this bug present after an update or on a fresh install?

Fresh Nextcloud Server install

Are you using the Nextcloud Server Encryption module?

Encryption is Disabled

What user-backends are you using?

• Default user-backend (database)
• LDAP/ Active Directory
• SSO - SAML
• Other

Configuration report

{
    "memcache.local": "\\OC\\Memcache\\APCu",
    "apps_paths": [
        {
            "path": "\/var\/www\/html\/apps",
            "url": "\/apps",
            "writable": false
        },
        {
            "path": "\/var\/www\/html\/custom_apps",
            "url": "\/custom_apps",
            "writable": true
        }
    ],
    "appsallowlist": false,
    "check_data_directory_permissions": false,
    "memcache.distributed": "\\OC\\Memcache\\Redis",
    "memcache.locking": "\\OC\\Memcache\\Redis",
    "redis": {
        "host": "***REMOVED SENSITIVE VALUE***",
        "password": "***REMOVED SENSITIVE VALUE***",
        "port": 6379
    },
    "overwriteprotocol": "https",
    "passwordsalt": "***REMOVED SENSITIVE VALUE***",
    "secret": "***REMOVED SENSITIVE VALUE***",
    "trusted_domains": [
        "localhost",
        "eaio1.minikube.test"
    ],
    "datadirectory": "***REMOVED SENSITIVE VALUE***",
    "dbtype": "pgsql",
    "version": "29.0.3.5",
    "overwrite.cli.url": "https:\/\/eaio1.minikube.test\/",
    "dbname": "***REMOVED SENSITIVE VALUE***",
    "dbhost": "***REMOVED SENSITIVE VALUE***",
    "dbport": "",
    "dbtableprefix": "oc_",
    "dbuser": "***REMOVED SENSITIVE VALUE***",
    "dbpassword": "***REMOVED SENSITIVE VALUE***",
    "installed": true,
    "instanceid": "***REMOVED SENSITIVE VALUE***",
    "maintenance": false,
    "loglevel": 2,
    "log_type": "file",
    "logfile": "\/var\/www\/html\/data\/nextcloud.log",
    "log_rotate_size": 10485760,
    "log.condition": {
        "apps": [
            "admin_audit"
        ]
    },
    "preview_max_x": 2048,
    "preview_max_y": 2048,
    "jpeg_quality": 60,
    "enabledPreviewProviders": {
        "1": "OC\\Preview\\Image",
        "2": "OC\\Preview\\MarkDown",
        "3": "OC\\Preview\\MP3",
        "4": "OC\\Preview\\TXT",
        "5": "OC\\Preview\\OpenDocument",
        "6": "OC\\Preview\\Movie",
        "7": "OC\\Preview\\Krita",
        "0": "OC\\Preview\\Imaginary"
    },
    "enable_previews": true,
    "upgrade.disable-web": true,
    "mail_smtpmode": "smtp",
    "trashbin_retention_obligation": "auto, 30",
    "versions_retention_obligation": "auto, 30",
    "activity_expire_days": 30,
    "simpleSignUpLink.shown": false,
    "share_folder": "\/Shared",
    "upgrade.cli-upgrade-link": "https:\/\/github.com\/nextcloud\/all-in-one\/discussions\/2726",
    "updatedirectory": "\/nc-updater",
    "maintenance_window_start": 100,
    "allow_local_remote_servers": true,
    "davstorage.request_timeout": 3600,
    "htaccess.RewriteBase": "\/",
    "dbpersistent": false,
    "auth.bruteforce.protection.enabled": true,
    "ratelimit.protection.enabled": true,
    "files_external_allow_create_new_local": false,
    "trusted_proxies": "***REMOVED SENSITIVE VALUE***",
    "preview_imaginary_url": "***REMOVED SENSITIVE VALUE***",
    "preview_imaginary_key": "***REMOVED SENSITIVE VALUE***",
    "config_is_read_only": true
}

List of activated Apps

No response

Nextcloud Signing status

No response

Nextcloud Logs

No response

Additional info

No response

Start by reproducing the app update through the web interface with config_is_read_only set in config.php, using the reported Nextcloud Server 29 setup. Trace the update flow from the web interface and determine why the read-only configuration prevents the expected app update. Done means the app updates successfully under this configuration without the reported error.