minor #11242 use UTF-8 instead of utf-8 (OskarStark)

This PR was merged into the 3.4 branch.

Discussion
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use UTF-8 instead of utf-8

Everywhere else we use `UTF-8`

Commits
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f1c624d use UTF-8 instead of utf-8

Author: OskarStark

components/translation/usage.rst

@@ -450,7 +450,7 @@ loaded/dumped when using this component inside a Symfony application:
 
 .. code-block:: xml
 
-    <?xml version="1.0" encoding="utf-8"?>
+    <?xml version="1.0" encoding="UTF-8"?>
     <xliff xmlns="urn:oasis:names:tc:xliff:document:2.0" version="2.0"
            srcLang="fr-FR" trgLang="en-US">
       <file id="messages.en_US">

doctrine/reverse_engineering.rst

@@ -73,7 +73,7 @@ The generated ``BlogPost.orm.xml`` metadata file looks as follows:
 
 .. code-block:: xml
 
-    <?xml version="1.0" encoding="utf-8"?>
+    <?xml version="1.0" encoding="UTF-8"?>
     <doctrine-mapping xmlns="http://doctrine-project.org/schemas/orm/doctrine-mapping" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://doctrine-project.org/schemas/orm/doctrine-mapping http://doctrine-project.org/schemas/orm/doctrine-mapping.xsd">
       <entity name="AppBundle\Entity\BlogPost" table="blog_post">
         <id name="id" type="bigint" column="id">

security/remember_me.rst

@@ -33,7 +33,7 @@ the session lasts using a cookie with the ``remember_me`` firewall option:
     .. code-block:: xml
 
         <!-- app/config/security.xml -->
-        <?xml version="1.0" encoding="utf-8" ?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:srv="http://symfony.com/schema/dic/services"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

service_container/tags.rst

@@ -81,7 +81,7 @@ If you want to apply tags automatically for your own services, use the
 
     .. code-block:: xml
 
-        <?xml version="1.0" encoding="utf-8"?>
+        <?xml version="1.0" encoding="UTF-8"?>
         <container xmlns="http://symfony.com/schema/dic/services" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://symfony.com/schema/dic/services https://symfony.com/schema/dic/services/services-1.0.xsd">
             <services>
                 <!-- this config only applies to the services created by this file -->

workflow/state-machines.rst

@@ -69,7 +69,7 @@ Below is the configuration for the pull request state machine.
     .. code-block:: xml
 
         <!-- app/config/config.xml -->
-        <?xml version="1.0" encoding="utf-8" ?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <container xmlns="http://symfony.com/schema/dic/services"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:framework="http://symfony.com/schema/dic/symfony"

workflow/usage.rst

@@ -55,7 +55,7 @@ like this:
     .. code-block:: xml
 
         <!-- app/config/config.xml -->
-        <?xml version="1.0" encoding="utf-8" ?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <container xmlns="http://symfony.com/schema/dic/services"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:framework="http://symfony.com/schema/dic/symfony"