The wikimedia-copyrightwarning message is used from WikimediaMessages, but that extension isn't a dependency of CommunityRequets. This causes ResourcesTest to fail when WikimediaMessages isn't installed:
./vendor/bin/phpunit tests/phpunit/structure/ResourcesTest.php --filter testMissingMessages Using PHP 8.3.6 Running with MediaWiki settings because there might be integration tests PHPUnit 9.6.21 by Sebastian Bergmann and contributors. F 1 / 1 (100%) Time: 00:00.753, Memory: 70.50 MB There was 1 failure: 1) ResourcesTest::testMissingMessages Message 'wikimedia-copyrightwarning' required by 'ext.communityrequests.intake' must exist Failed asserting that false is true. mediawiki/tests/phpunit/structure/ResourcesTest.php:119
To fix this, a new message should be added, called communityrequests-copyrightwarning, which can then be overridden in the ResourceLoader factory in AbstractWishlistSpecialPage if WikimediaMessages is installed.