[FrameworkBundle] Assets templating helper does not need request scope

No other helpers have request scope and the assets helper's parameters don't appear to depend on the request in any way, so this appears to be unnecessary. As-is, request scope here prevents use of the assets helper from a console command that may need to internally render a template.

src/Symfony/Bundle/FrameworkBundle/Resources/config/templating_php.xml

@@ -34,7 +34,7 @@
             <tag name="templating.helper" alias="slots" />
         </service>
 
-        <service id="templating.helper.assets" class="%templating.helper.assets.class%" scope="request">
+        <service id="templating.helper.assets" class="%templating.helper.assets.class%">
             <tag name="templating.helper" alias="assets" />
             <argument /> <!-- default package -->
             <argument type="collection" /> <!-- named packages -->