Removed \"experimental\" notices in some components

Author: javiereguiluz

components/http_client.rst

@@ -11,8 +11,7 @@ The HttpClient Component
 
 .. versionadded:: 4.3
 
-    The HttpClient component was introduced in Symfony 4.3 and it's still
-    considered an :doc:`experimental feature </contributing/code/experimental>`.
+    The HttpClient component was introduced in Symfony 4.3.
 
 Installation
 ------------

components/mailer.rst

@@ -9,8 +9,7 @@ The Mailer Component
 
 .. versionadded:: 4.3
 
-    The Mailer component was introduced in Symfony 4.3 and it's still
-    considered an :doc:`experimental feature </contributing/code/experimental>`.
+    The Mailer component was introduced in Symfony 4.3.
 
 Installation
 ------------

components/mime.rst

@@ -11,8 +11,7 @@ The Mime Component
 
 .. versionadded:: 4.3
 
-    The Mime component was introduced in Symfony 4.3 and it's still
-    considered an :doc:`experimental feature </contributing/code/experimental>`.
+    The Mime component was introduced in Symfony 4.3.
 
 Installation
 ------------

mailer.rst

@@ -3,17 +3,12 @@ Sending Emails with Mailer
 
 .. versionadded:: 4.3
 
-    The Mailer component was added in Symfony 4.3 and is currently experimental.
-    The previous solution - Swift Mailer - is still valid: :doc:`Swift Mailer</email>`.
+    The Mailer component was introduced in Symfony 4.3. The previous solution,
+    called Swift Mailer, is still valid: :doc:`Swift Mailer</email>`.
 
 Installation
 ------------
 
-.. caution::
-
-    The Mailer component is experimental in Symfony 4.3: some backwards compatibility
-    breaks could occur before 4.4.
-
 Symfony's Mailer & :doc:`Mime </components/mime>` components form a *powerful* system
 for creating and sending emails - complete with support for multipart messages, Twig
 integration, CSS inlining, file attachments and a lot more. Get them installed with: