29 files declare their use of StateInterface in Feeds 8.3

CleanStateInterface.php in src/Feeds/State/CleanStateInterface.php

ClearableInterface.php in src/Plugin/Type/ClearableInterface.php

ConfigEntityReference.php in src/Feeds/Target/ConfigEntityReference.php

CsvParser.php in src/Feeds/Parser/CsvParser.php

CsvParserTest.php in tests/src/Unit/Feeds/Parser/CsvParserTest.php

DirectoryFetcher.php in src/Feeds/Fetcher/DirectoryFetcher.php

EntityProcessorBase.php in src/Feeds/Processor/EntityProcessorBase.php

EntityProcessorBaseTest.php in tests/src/Kernel/Feeds/Processor/EntityProcessorBaseTest.php

EntityReference.php in src/Feeds/Target/EntityReference.php

Feed.php in src/Entity/Feed.php

FeedClearHandlerTest.php in tests/src/Unit/FeedClearHandlerTest.php

FeedRefreshTest.php in tests/src/Unit/Plugin/QueueWorker/FeedRefreshTest.php

FeedsExecutableTest.php in tests/src/Unit/FeedsExecutableTest.php

FeedTest.php in tests/src/Kernel/Entity/FeedTest.php

FetcherInterface.php in src/Plugin/Type/Fetcher/FetcherInterface.php

HttpFetcher.php in src/Feeds/Fetcher/HttpFetcher.php

LazySubscriber.php in src/EventSubscriber/LazySubscriber.php

OpmlParser.php in src/Feeds/Parser/OpmlParser.php

ParserInterface.php in src/Plugin/Type/Parser/ParserInterface.php

ParserWithMappingForm.php in tests/modules/feeds_test_plugin/src/Feeds/Parser/ParserWithMappingForm.php

ProcessorBase.php in src/Feeds/Processor/ProcessorBase.php

ProcessorInterface.php in src/Plugin/Type/Processor/ProcessorInterface.php

SitemapParser.php in src/Feeds/Parser/SitemapParser.php

SkipNewTest.php in tests/src/Kernel/SkipNewTest.php

StateTest.php in tests/src/Unit/StateTest.php

SyndicationParser.php in src/Feeds/Parser/SyndicationParser.php

UpdateNonExistentTest.php in tests/src/Kernel/UpdateNonExistentTest.php

UploadFetcher.php in src/Feeds/Fetcher/UploadFetcher.php

UploadFetcherTest.php in tests/src/Unit/Feeds/Fetcher/UploadFetcherTest.php