refactor: deprecate CodeIgniter\HTTP\ContentSecurityPolicy::$nonces since never used (codeigniter4#9905)

Author: paulbalandan

system/HTTP/ContentSecurityPolicy.php

@@ -223,6 +223,8 @@ class ContentSecurityPolicy
      * Set of nonces generated.
      *
      * @var list<string>
+     *
+     * @deprecated 4.7.0 Never used.
      */
     protected $nonces = [];
 

user_guide_src/source/changelogs/v4.7.0.rst

@@ -375,6 +375,8 @@ Changes
 Deprecations
 ************
 
+- **ContentSecurityPolicy:**
+    - The ``CodeIgniter\HTTP\ContentSecurityPolicy::$nonces`` property has been deprecated. It was never used.
 - **Encryption:**
     - The method ``CodeIgniter\Encryption\Handlers\SodiumHandler::parseParams()`` has been deprecated. Parameters are now handled directly in ``encrypt()`` and ``decrypt()`` methods.
 - **Image:**