feature #6406 Added a note about the new "disabled" option for PHPUnitBridge (javiereguiluz)

This PR was squashed before being merged into the master branch (closes #6406).

Discussion
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Added a note about the new "disabled" option for PHPUnitBridge

This fixes #6386.

Commits
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e924dd8 Added a note about the new "disabled" option for PHPUnitBridge

Author: wouterj

components/phpunit_bridge.rst

@@ -112,7 +112,7 @@ PHPUnit_ will stop your test suite once a deprecation notice is triggered whose
 message contains the ``"foobar"`` string.
 
 Making Tests Fail
------------------
+~~~~~~~~~~~~~~~~~
 
 By default, any non-legacy-tagged or any non-`@-silenced`_ deprecation notices
 will make tests fail. Alternatively, setting ``SYMFONY_DEPRECATIONS_HELPER`` to
@@ -122,6 +122,14 @@ also set the value ``"weak"`` which will make the bridge ignore any deprecation
 notices. This is useful to projects that must use deprecated interfaces for
 backward compatibility reasons.
 
+Disabling the Deprecation Helper
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Set the ``SYMFONY_DEPRECATIONS_HELPER`` environment variable to ``disabled`` to
+completely disable the deprecation helper. This is useful to make use of the
+rest of features provided by this component without getting errors or messages
+related to deprecations.
+
 Time-sensitive Tests
 --------------------