8 files declare their use of FieldException in Drupal 10

EntityDefinitionUpdateTest.php in core/tests/Drupal/KernelTests/Core/Entity/EntityDefinitionUpdateTest.php

EntityReferenceItem.php in core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EntityReferenceItem.php

field.purge.inc in core/modules/field/field.purge.inc

Provides support for field data purge after mass deletion.

FieldCrudTest.php in core/modules/field/tests/src/Kernel/FieldCrudTest.php

FieldStorageConfigEntityUnitTest.php in core/modules/field/tests/src/Unit/FieldStorageConfigEntityUnitTest.php

Contains \Drupal\Tests\field\Unit\FieldStorageConfigEntityUnitTest.

FieldStorageConfigUpdateForbiddenException.php in core/modules/field/src/FieldStorageConfigUpdateForbiddenException.php

FieldStorageCrudTest.php in core/modules/field/tests/src/Kernel/FieldStorageCrudTest.php

SqlContentEntityStorageSchema.php in core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorageSchema.php