6 files declare their use of FieldResolver in JSON:API 8

FilterNormalizer.php in src/Normalizer/FilterNormalizer.php

FilterNormalizerTest.php in tests/src/Kernel/Normalizer/FilterNormalizerTest.php

JsonApiDocumentTopLevelNormalizer.php in src/Normalizer/JsonApiDocumentTopLevelNormalizer.php

JsonApiDocumentTopLevelNormalizerTest.php in tests/src/Unit/Normalizer/JsonApiDocumentTopLevelNormalizerTest.php

SortNormalizer.php in src/Normalizer/SortNormalizer.php

SortNormalizerTest.php in tests/src/Kernel/Normalizer/SortNormalizerTest.php