feature #39557 [Notifier] [BC BREAK] Final classes (OskarStark)

This PR was merged into the 5.3-dev branch.

Discussion
----------

[Notifier] [BC BREAK] Final classes

| Q             | A
| ------------- | ---
| Branch?       | 5.x
| Bug fix?      | no
| New feature?  | no, BC BREAK, but experimental <!-- please update src/**/CHANGELOG.md files -->
| Deprecations? | no <!-- please update UPGRADE-*.md and src/**/CHANGELOG.md files -->
| Tickets       | ---
| License       | MIT
| Doc PR        | ---

Commits
-------

733ba619a1 [Notifier] [BC BREAK] Final classes

src/Symfony/Component/Notifier/Bridge/LinkedIn/CHANGELOG.md

@@ -5,6 +5,7 @@ CHANGELOG
 -----
 
  * The bridge is not marked as `@experimental` anymore
+* [BC BREAK] `LinkedInTransportFactory` is now final
 
 5.2.0
 -----

src/Symfony/Component/Notifier/Bridge/LinkedIn/LinkedInTransportFactory.php

@@ -19,7 +19,7 @@ use Symfony\Component\Notifier\Transport\TransportInterface;
 /**
  * @author Smaïne Milianni <smaine.milianni@gmail.com>
  */
-class LinkedInTransportFactory extends AbstractTransportFactory
+final class LinkedInTransportFactory extends AbstractTransportFactory
 {
     public function create(Dsn $dsn): TransportInterface
     {

src/Symfony/Component/Notifier/Bridge/Smsapi/CHANGELOG.md

@@ -0,0 +1,7 @@
+CHANGELOG
+=========
+
+5.3.0
+-----
+
+ * Added the bridge

src/Symfony/Component/Notifier/Bridge/Smsapi/SmsapiTransport.php

@@ -22,6 +22,8 @@ use Symfony\Contracts\HttpClient\HttpClientInterface;
 
 /**
  * @author Marcin Szepczynski <szepczynski@gmail.com>
+ *
+ * @experimental in 5.3
  */
 final class SmsapiTransport extends AbstractTransport
 {

src/Symfony/Component/Notifier/Bridge/Smsapi/SmsapiTransportFactory.php

@@ -19,8 +19,10 @@ use Symfony\Component\Notifier\Transport\TransportInterface;
 
 /**
  * @author Marcin Szepczynski <szepczynski@gmail.com>
+ *
+ * @experimental in 5.3
  */
-class SmsapiTransportFactory extends AbstractTransportFactory
+final class SmsapiTransportFactory extends AbstractTransportFactory
 {
     /**
      * @return SmsapiTransport

src/Symfony/Component/Notifier/Bridge/Zulip/CHANGELOG.md

@@ -5,6 +5,8 @@ CHANGELOG
 -----
 
  * The bridge is not marked as `@experimental` anymore
+* [BC BREAK] `ZulipTransport` is now final
+* [BC BREAK] `ZulipTransportFactory` is now final
 
 5.2.0
 -----

src/Symfony/Component/Notifier/Bridge/Zulip/ZulipTransport.php

@@ -24,7 +24,7 @@ use Symfony\Contracts\HttpClient\HttpClientInterface;
 /**
  * @author Mohammad Emran Hasan <phpfour@gmail.com>
  */
-class ZulipTransport extends AbstractTransport
+final class ZulipTransport extends AbstractTransport
 {
     private $email;
     private $token;

src/Symfony/Component/Notifier/Bridge/Zulip/ZulipTransportFactory.php

@@ -20,7 +20,7 @@ use Symfony\Component\Notifier\Transport\TransportInterface;
 /**
  * @author Mohammad Emran Hasan <phpfour@gmail.com>
  */
-class ZulipTransportFactory extends AbstractTransportFactory
+final class ZulipTransportFactory extends AbstractTransportFactory
 {
     /**
      * @return ZulipTransport