Issue #3276255 by phenaproxima: Disable unattended updates until TUF integration is complete

automatic_updates.module

automatic_updates.services.yml

src/CronUpdater.php

src/Validation/AdminReadinessMessages.php

src/Validation/ReadinessValidationManager.php

src/Validator/CronFrequencyValidator.php

src/Validator/CronUpdateVersionValidator.php

...ic_updates_test_cron/automatic_updates_test_cron.info.yml

...atic_updates_test_cron/automatic_updates_test_cron.module

...pdates_test_cron/automatic_updates_test_cron.services.yml

tests/modules/automatic_updates_test_cron/src/Enabler.php

tests/src/Build/UpdateTestBase.php

tests/src/Functional/AutomaticUpdatesFunctionalTestBase.php

tests/src/Kernel/AutomaticUpdatesKernelTestBase.php

...Kernel/ReadinessValidation/CronFrequencyValidatorTest.php