Issue #2962736 by idebr: phpunit.xml.dist has an incorrect instruction on how...

Issue #2962736 by idebr: phpunit.xml.dist has an incorrect instruction on how to disable deprecation errors

core/phpunit.xml.dist

@@ -28,7 +28,7 @@
     <env name="SIMPLETEST_DB" value=""/>
     <!-- Example BROWSERTEST_OUTPUT_DIRECTORY value: /path/to/webroot/sites/simpletest/browser_output -->
     <env name="BROWSERTEST_OUTPUT_DIRECTORY" value=""/>
-    <!-- To disable deprecation testing uncomment the next line. -->
+    <!-- To disable deprecation testing completely set SYMFONY_DEPRECATIONS_HELPER value: 'disabled' -->
     <env name="SYMFONY_DEPRECATIONS_HELPER" value="weak_vendors"/>
     <!-- Example for changing the driver class for mink tests MINK_DRIVER_CLASS value: 'Drupal\FunctionalJavascriptTests\DrupalSelenium2Driver' -->
     <!-- Example for changing the driver args to mink tests MINK_DRIVER_ARGS value: '["http://127.0.0.1:8510"]' -->