Issue #2294083 by ParisLiakos: Remove usages of module_uninstall().

...ules/aggregator/src/Tests/AggregatorConfigurationTest.php

core/modules/aggregator/src/Tests/UpdateFeedItemTest.php

core/modules/config/src/Tests/ConfigInstallWebTest.php

core/modules/system/src/Tests/Entity/EntityApiInfoTest.php

...dules/system/src/Tests/Form/LanguageSelectElementTest.php

core/modules/system/src/Tests/Module/ClassLoaderTest.php

core/modules/system/src/Tests/Module/UninstallTest.php

core/modules/taxonomy/src/Tests/VocabularyCrudTest.php