6 files declare their use of Query in Search API 8

AddHierarchyTest.php in tests/src/Kernel/Processor/AddHierarchyTest.php

NumberFieldBoostTest.php in tests/src/Kernel/Processor/NumberFieldBoostTest.php

QueryHelper.php in src/Utility/QueryHelper.php

QueryTest.php in tests/src/Kernel/System/QueryTest.php

TestItemsTrait.php in tests/src/Unit/Processor/TestItemsTrait.php

TokenizerTest.php in tests/src/Unit/Processor/TokenizerTest.php