9 files declare their use of OutboundPathProcessorInterface in Drupal 10

AliasPathProcessor.php in core/modules/path_alias/src/PathProcessor/AliasPathProcessor.php

LanguageNegotiationContentEntity.php in core/modules/language/src/Plugin/LanguageNegotiation/LanguageNegotiationContentEntity.php

LanguageNegotiationSession.php in core/modules/language/src/Plugin/LanguageNegotiation/LanguageNegotiationSession.php

LanguageNegotiationUrl.php in core/modules/language/src/Plugin/LanguageNegotiation/LanguageNegotiationUrl.php

PathProcessorLanguage.php in core/modules/language/src/HttpKernel/PathProcessorLanguage.php

PathProcessorTest.php in core/modules/system/tests/modules/url_alter_test/src/PathProcessorTest.php

UnroutedUrlAssembler.php in core/lib/Drupal/Core/Utility/UnroutedUrlAssembler.php

UrlGenerator.php in core/lib/Drupal/Core/Routing/UrlGenerator.php

UrlGeneratorTest.php in core/tests/Drupal/Tests/Core/Routing/UrlGeneratorTest.php