minor #41933 [DependencyInjection] Turn $defaultDeprecationTemplate into a constant (derrabus)

This PR was merged into the 4.4 branch.

Discussion
----------

[DependencyInjection] Turn $defaultDeprecationTemplate into a constant

| Q             | A
| ------------- | ---
| Branch?       | 4.4
| Bug fix?      | no
| New feature?  | no
| Deprecations? | no
| Tickets       | symfony/symfony#41928 (comment)
| License       | MIT
| Doc PR        | N/A

Commits
-------

936e399ff9 [DependencyInjection] Turn $defaultDeprecationTemplate into a constant

Author: fabpot

Alias.php

@@ -15,14 +15,14 @@
 
 class Alias
 {
+    private const DEFAULT_DEPRECATION_TEMPLATE = 'The "%alias_id%" service alias is deprecated. You should stop using it, as it will be removed in the future.';
+
     private $id;
     private $public;
     private $private;
     private $deprecated;
     private $deprecationTemplate;
 
-    private static $defaultDeprecationTemplate = 'The "%alias_id%" service alias is deprecated. You should stop using it, as it will be removed in the future.';
-
     public function __construct(string $id, bool $public = true)
     {
         $this->id = $id;
@@ -122,7 +122,7 @@ public function isDeprecated(): bool
 
     public function getDeprecationMessage(string $id): string
     {
-        return str_replace('%alias_id%', $id, $this->deprecationTemplate ?: self::$defaultDeprecationTemplate);
+        return str_replace('%alias_id%', $id, $this->deprecationTemplate ?: self::DEFAULT_DEPRECATION_TEMPLATE);
     }
 
     /**

Definition.php

@@ -22,6 +22,8 @@
  */
 class Definition
 {
+    private const DEFAULT_DEPRECATION_TEMPLATE = 'The "%service_id%" service is deprecated. You should stop using it, as it will be removed in the future.';
+
     private $class;
     private $file;
     private $factory;
@@ -47,8 +49,6 @@ class Definition
 
     protected $arguments = [];
 
-    private static $defaultDeprecationTemplate = 'The "%service_id%" service is deprecated. You should stop using it, as it will be removed in the future.';
-
     /**
      * @internal
      *
@@ -799,7 +799,7 @@ public function isDeprecated()
      */
     public function getDeprecationMessage($id)
     {
-        return str_replace('%service_id%', $id, $this->deprecationTemplate ?: self::$defaultDeprecationTemplate);
+        return str_replace('%service_id%', $id, $this->deprecationTemplate ?: self::DEFAULT_DEPRECATION_TEMPLATE);
     }
 
     /**