Issue #3317385 by phenaproxima, tedbow: Remove staged fixtures from StagedProjectsValidatorTest

...r/tests/fixtures/fake_site/vendor/composer/installed.json

package_manager/tests/src/Kernel/FixtureUtilityTraitTest.php

package_manager/tests/src/Traits/FixtureUtilityTrait.php

tests/fixtures/StagedProjectsValidatorTest/README.md

...t/new_project_added/staged/vendor/composer/installed.json

...st/new_project_added/staged/vendor/composer/installed.php

...atorTest/new_project_added/vendor/composer/installed.json

...datorTest/new_project_added/vendor/composer/installed.php

...datorTest/no_errors/staged/vendor/composer/installed.json

...idatorTest/no_errors/staged/vendor/composer/installed.php

...ctsValidatorTest/no_errors/vendor/composer/installed.json

...est/project_removed/staged/vendor/composer/installed.json

...idatorTest/project_removed/vendor/composer/installed.json

...est/version_changed/staged/vendor/composer/installed.json

...idatorTest/version_changed/vendor/composer/installed.json

tests/src/Kernel/StatusCheck/StagedProjectsValidatorTest.php