Issue #3515715 by quietone: Fix 'DocComment.MissingShort' in Unit tests

...tests/src/Unit/Render/Placeholder/BigPipeStrategyTest.php

core/modules/block/tests/src/Unit/BlockRepositoryTest.php

core/modules/ckeditor5/tests/src/Unit/VersionTest.php

...modules/comment/tests/src/Unit/CommentLinkBuilderTest.php

core/modules/contact/tests/src/Unit/ContactTest.php

...t_moderation/tests/src/Unit/ModerationInformationTest.php

...ules/field/tests/src/Unit/FieldUninstallValidatorTest.php

...ests/src/Unit/Plugin/migrate/process/ProcessFieldTest.php

...es/field_layout/tests/src/Unit/FieldLayoutBuilderTest.php

.../tests/src/Unit/Plugin/migrate/field/d6/FileFieldTest.php

.../tests/src/Unit/Plugin/migrate/field/d7/FileFieldTest.php

...ests/src/Unit/Plugin/migrate/process/d6/FieldFileTest.php

core/modules/filter/tests/src/Unit/FilterHtmlTest.php

...modules/filter/tests/src/Unit/FilterImageLazyLoadTest.php

...es/filter/tests/src/Unit/FilterUninstallValidatorTest.php

core/modules/image/tests/src/Unit/ImageDeprecationTest.php

.../tests/src/Unit/Plugin/migrate/field/d6/LinkFieldTest.php

...k/tests/src/Unit/Plugin/migrate/process/FieldLinkTest.php

...odules/locale/tests/src/Unit/LocaleProjectStorageTest.php

core/modules/media/tests/src/Unit/ResourceFetcherTest.php