minor #15770 Note that parameter names for Attribute constructors are covered (mbabker)

This PR was merged into the 4.4 branch.

Discussion
----------

Note that parameter names for Attribute constructors are covered

Fixes #15757

Commits
-------

0463e58 Note that parameter names for Attribute constructors are covered

Author: javiereguiluz

contributing/code/bc.rst

@@ -448,8 +448,8 @@ Turn static into non static                         No
 
 .. [9] Allowed for the ``void`` return type.
 
-.. [10] Parameter names are not part of the compatibility promise. Using
-        PHP 8's named arguments feature might break your code when upgrading to
-        newer Symfony versions.
+.. [10] Parameter names are only covered by the compatibility promise for
+        constructors of Attribute classes. Using PHP 8's named arguments
+        feature might break your code when upgrading to newer Symfony versions.
 
 .. _`Semantic Versioning`: https://semver.org/