Issue #3086369 by zrpnr, lauriii, Wim Leers: Deprecate matchMedia

core/core.libraries.yml

@@ -889,6 +889,7 @@ matchmedia:
     gpl-compatible: true
   js:
     assets/vendor/matchMedia/matchMedia.min.js: { minified: true }
+  deprecated: &matchmedia_deprecated The "%library_id%" asset library is deprecated in drupal:8.8.0 and is removed from drupal:9.0.0. See https://www.drupal.org/node/3086653
 
 matchmedia.addListener:
   version: *matchmedia_version
@@ -897,6 +898,7 @@ matchmedia.addListener:
     assets/vendor/matchMedia/matchMedia.addListener.min.js: { minified: true }
   dependencies:
     - core/matchmedia
+  deprecated: *matchmedia_deprecated
 
 modernizr:
   # Block the page from being loaded until Modernizr is initialized.

core/tests/Drupal/Tests/Listeners/DeprecationListenerTrait.php

@@ -143,6 +143,8 @@ public static function getSkippedDeprecations() {
       // @todo Remove in https://www.drupal.org/project/drupal/issues/3082655
       'Drupal\Tests\BrowserTestBase::$defaultTheme is required in drupal:9.0.0 when using an install profile that does not set a default theme. See https://www.drupal.org/node/2352949, which includes recommendations on which theme to use.',
       'The "core/html5shiv" asset library is deprecated in drupal:8.8.0 and is removed from drupal:9.0.0. See https://www.drupal.org/node/3086383',
+      'The "core/matchmedia" asset library is deprecated in drupal:8.8.0 and is removed from drupal:9.0.0. See https://www.drupal.org/node/3086653',
+      'The "core/matchmedia.addListener" asset library is deprecated in drupal:8.8.0 and is removed from drupal:9.0.0. See https://www.drupal.org/node/3086653',
     ];
   }