minor symfony#18245 [DependencyInjection] Update changelog (dunglas)

This PR was merged into the 2.8 branch.

Discussion
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[DependencyInjection] Update changelog

| Q             | A
| ------------- | ---
| Branch?       | 2.8
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | n/a
| License       | MIT
| Doc PR        | n/a

Commits
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3de481d [DependencyInjection] Update changelog

Author: nicolas-grekas

src/Symfony/Component/DependencyInjection/CHANGELOG.md

@@ -11,6 +11,7 @@ CHANGELOG
  * added `Definition::setShared()` and `Definition::isShared()`
  * added ResettableContainerInterface to be able to reset the container to release memory on shutdown
  * added a way to define the priority of service decoration
+ * added support for service autowiring
 
 2.7.0
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