13 files declare their use of ExtensionLifecycle in Drupal 9

DefaultConfigTest.php in core/tests/Drupal/KernelTests/Config/DefaultConfigTest.php

EntityResourceRestTestCoverageTest.php in core/modules/rest/tests/src/Functional/EntityResource/EntityResourceRestTestCoverageTest.php

HelpController.php in core/modules/help/src/Controller/HelpController.php

HelpTopicsSyntaxTest.php in core/modules/help_topics/tests/src/Functional/HelpTopicsSyntaxTest.php

InfoParserUnitTest.php in core/tests/Drupal/Tests/Core/Extension/InfoParserUnitTest.php

InstallUninstallTest.php in core/modules/system/tests/src/Functional/Module/InstallUninstallTest.php

ModulesListForm.php in core/modules/system/src/Form/ModulesListForm.php

Stable9LibraryOverrideTest.php in core/tests/Drupal/KernelTests/Core/Theme/Stable9LibraryOverrideTest.php

Stable9TemplateOverrideTest.php in core/tests/Drupal/KernelTests/Core/Theme/Stable9TemplateOverrideTest.php

StableLibraryOverrideTest.php in core/tests/Drupal/KernelTests/Core/Theme/StableLibraryOverrideTest.php

StableTemplateOverrideTest.php in core/tests/Drupal/KernelTests/Core/Theme/StableTemplateOverrideTest.php

system.install in core/modules/system/system.install

Install, update and uninstall functions for the system module.

TestCoverageTest.php in core/modules/jsonapi/tests/src/Functional/TestCoverageTest.php