Merge branch '5.4' into 6.0

* 5.4:
  Fix CS in README files
  Fix markdown
  [HttpKernel] Fixes tests for PHP7.4+
  fix test
  [HttpKernel] Throw when HttpKernel is created and the env is empty
  [FrameworkBundle] Deprecate the `AdapterInterface` autowiring alias, use `CacheItemPoolInterface` instead
  [Filesystem] fix readlink for Windows

Author: nicolas-grekas

README.md

@@ -31,8 +31,8 @@ It also provides a few improvements over `var_export()`/`serialize()`:
 Resources
 ---------
 
-  * [Documentation](https://symfony.com/doc/current/components/var_exporter.html)
-  * [Contributing](https://symfony.com/doc/current/contributing/index.html)
-  * [Report issues](https://github.com/symfony/symfony/issues) and
-    [send Pull Requests](https://github.com/symfony/symfony/pulls)
-    in the [main Symfony repository](https://github.com/symfony/symfony)
+ * [Documentation](https://symfony.com/doc/current/components/var_exporter.html)
+ * [Contributing](https://symfony.com/doc/current/contributing/index.html)
+ * [Report issues](https://github.com/symfony/symfony/issues) and
+   [send Pull Requests](https://github.com/symfony/symfony/pulls)
+   in the [main Symfony repository](https://github.com/symfony/symfony)