Merge branch '5.4' into 6.4

* 5.4:
  [DependencyInjection] Add readonly statement to the Lazy Services docs
  [Logger] Using LogLevel `const`s, Part 2

Author: javiereguiluz

logging.rst

@@ -164,7 +164,7 @@ to write logs using the :phpfunction:`syslog` function:
                 ->type('stream')
                 // log to var/logs/(environment).log
                 ->path('%kernel.logs_dir%/%kernel.environment%.log')
-                // log *all* messages (debug is lowest level)
+                // log *all* messages (LogLevel::DEBUG is lowest level)
                 ->level(LogLevel::DEBUG);
 
             $monolog->handler('syslog_handler')
@@ -255,31 +255,32 @@ one of the messages reaches an ``action_level``. Take this example:
     .. code-block:: php
 
         // config/packages/prod/monolog.php
+        use Psr\Log\LogLevel;
         use Symfony\Config\MonologConfig;
 
         return static function (MonologConfig $monolog): void {
             $monolog->handler('filter_for_errors')
                 ->type('fingers_crossed')
                 // if *one* log is error or higher, pass *all* to file_log
-                ->actionLevel('error')
+                ->actionLevel(LogLevel::ERROR)
                 ->handler('file_log')
             ;
 
             // now passed *all* logs, but only if one log is error or higher
             $monolog->handler('file_log')
                 ->type('stream')
                 ->path('%kernel.logs_dir%/%kernel.environment%.log')
-                ->level('debug')
+                ->level(LogLevel::DEBUG)
             ;
 
             // still passed *all* logs, and still only logs error or higher
             $monolog->handler('syslog_handler')
                 ->type('syslog')
-                ->level('error')
+                ->level(LogLevel::ERROR)
             ;
         };
 
-Now, if even one log entry has an ``error`` level or higher, then *all* log entries
+Now, if even one log entry has an ``LogLevel::ERROR`` level or higher, then *all* log entries
 for that request are saved to a file via the ``file_log`` handler. That means that
 your log file will contain *all* the details about the problematic request - making
 debugging much easier!
@@ -350,13 +351,14 @@ option of your handler to ``rotating_file``:
     .. code-block:: php
 
         // config/packages/prod/monolog.php
+        use Psr\Log\LogLevel;
         use Symfony\Config\MonologConfig;
 
         return static function (MonologConfig $monolog): void {
             $monolog->handler('main')
                 ->type('rotating_file')
                 ->path('%kernel.logs_dir%/%kernel.environment%.log')
-                ->level('debug')
+                ->level(LogLevel::DEBUG)
                 // max number of log files to keep
                 // defaults to zero, which means infinite files
                 ->maxFiles(10);

service_container/lazy_services.rst

@@ -23,7 +23,7 @@ until you interact with the proxy in some way.
 
 .. caution::
 
-    Lazy services do not support `final`_ classes, but you can use
+    Lazy services do not support `final`_ or ``readonly`` classes, but you can use
     `Interface Proxifying`_ to work around this limitation.
 
     In PHP versions prior to 8.0 lazy services do not support parameters with