Update changelog

CHANGELOG.md

@@ -1,3 +1,17 @@
+### [2.0.9] 2021-01-27
+
+  * Added warning if the curl extension is not enabled as it significantly degrades performance
+  * Fixed InstalledVersions to report all packages when several vendor dirs are present in the same runtime
+  * Fixed download speed when downloading large files
+  * Fixed `archive` and path repo copies mishandling some .gitignore paths
+  * Fixed root package classes not being available to the plugins/scripts during the initial install
+  * Fixed cache writes to be atomic and better support multiple Composer processes running in parallel
+  * Fixed preg jit issues when `config` or `require` modifies large composer.json files
+  * Fixed compatibility with envs having open_basedir restrictions
+  * Fixed exclude-from-classmap causing regex issues when having too many paths
+  * Fixed compatibility issue with Symfony 4/5
+  * Several small performance and debug output improvements
+
 ### [2.0.8] 2020-12-03
 
   * Fixed packages with aliases not matching conflicts which match the alias
@@ -1081,6 +1095,7 @@
 
   * Initial release
 
+[2.0.9]: https://github.com/composer/composer/compare/2.0.8...2.0.9
 [2.0.8]: https://github.com/composer/composer/compare/2.0.7...2.0.8
 [2.0.7]: https://github.com/composer/composer/compare/2.0.6...2.0.7
 [2.0.6]: https://github.com/composer/composer/compare/2.0.5...2.0.6