Issue #3298349 by rahul_: Do not use generic `@return array[]` when types are known

automatic_updates_extensions/src/Form/UpdaterForm.php

...dates_extensions/tests/src/Functional/UpdaterFormTest.php

.../Validator/PackagesInstalledWithComposerValidatorTest.php

.../src/Kernel/Validator/UpdatePackagesTypeValidatorTest.php

...tests/src/Kernel/Validator/UpdateReleaseValidatorTest.php

package_manager/src/Validator/DiskSpaceValidator.php

...tests/fixtures/updated_module/1.0.0/updated_module.module

...tests/fixtures/updated_module/1.1.0/updated_module.module

.../package_manager_bypass/src/BypassedStagerServiceBase.php

package_manager/tests/src/Build/TemplateProjectTestBase.php

...ager/tests/src/Kernel/ComposerExecutableValidatorTest.php

...anager/tests/src/Kernel/ComposerSettingsValidatorTest.php

package_manager/tests/src/Kernel/ComposerUtilityTest.php

package_manager/tests/src/Kernel/LockFileValidatorTest.php

package_manager/tests/src/Kernel/MultisiteValidatorTest.php

...ts/src/Kernel/PathExcluder/SqliteDatabaseExcluderTest.php

package_manager/tests/src/Kernel/SettingsValidatorTest.php

package_manager/tests/src/Kernel/StageTest.php

...manager/tests/src/Kernel/StageValidationExceptionTest.php

...ager/tests/src/Kernel/WritableFileSystemValidatorTest.php