[meta] Make 9.0.x branch pass testbot

Problem/Motivation

Meta to track child issues

Proposed resolution

1. ✅ #3072702: Core extensions should not need to specify the new core_version_requirement in *.info.yml files so that 9.0.x can be installed
2. ✅ #3087991: Drupal\Tests\system\Functional\Update\UpdatePathTestBaseFilledTest::testUpdateHookN Failed asserting that 8000 matches expected 8001.
3. ✅ #3088012: InstallerExistingConfigTest shouldn't download translations from l.d.o
4. ✅ #3088127: Fix FileTransferAuthorizeFormTest and UpdateUploadTest on 9.0.x
5. ✅ #3088135: TestSiteApplicationTest::testInstallInDifferentLanguage requires localize.drupal.org

Remaining tasks

User interface changes

API changes

Data model changes

Release notes snippet