9 files declare their use of PathMatcherInterface in Drupal 9

ActiveLinkResponseFilter.php in core/lib/Drupal/Core/EventSubscriber/ActiveLinkResponseFilter.php

ActiveLinkResponseFilterTest.php in core/tests/Drupal/Tests/Core/EventSubscriber/ActiveLinkResponseFilterTest.php

IsFrontPathCacheContext.php in core/lib/Drupal/Core/Cache/Context/IsFrontPathCacheContext.php

IsFrontPathCacheContextTest.php in core/tests/Drupal/Tests/Core/Cache/Context/IsFrontPathCacheContextTest.php

LanguageBlock.php in core/modules/language/src/Plugin/Block/LanguageBlock.php

PathBasedBreadcrumbBuilder.php in core/modules/system/src/PathBasedBreadcrumbBuilder.php

PathBasedBreadcrumbBuilderTest.php in core/modules/system/tests/src/Unit/Breadcrumbs/PathBasedBreadcrumbBuilderTest.php

Contains \Drupal\Tests\system\Unit\Breadcrumbs\PathBasedBreadcrumbBuilderTest.

RegistryTest.php in core/tests/Drupal/KernelTests/Core/Theme/RegistryTest.php

RequestPath.php in core/modules/system/src/Plugin/Condition/RequestPath.php