Added 4.0.9 release announcement

Author: hsbt

_posts/2026-03-25-4.0.9-released.md

@@ -0,0 +1,67 @@
+---
+title: 4.0.9 Released
+layout: post
+author: Hiroshi SHIBATA
+author_email: hsbt@ruby-lang.org
+---
+
+RubyGems 4.0.9 includes enhancements, bug fixes and documentation and Bundler 4.0.9 includes enhancements and bug fixes.
+
+To update to the latest RubyGems you can run:
+
+    gem update --system [--pre]
+
+To update to the latest Bundler you can run:
+
+    gem install bundler [--pre]
+    bundle update --bundler=4.0.9
+
+## RubyGems Release Notes
+
+
+### Enhancements:
+
+* Fix: include owner role in `gem owner`. Pull request [#9403](https://github.com/ruby/rubygems/pull/9403) by gjtorikian
+* Installs bundler 4.0.9 as a default gem.
+
+### Bug fixes:
+
+* Fix: Ensure trailing slash is added to source URIs added via gem sources. Pull request [#9055](https://github.com/ruby/rubygems/pull/9055) by zirni
+
+### Documentation:
+
+* [DOC] Fix link. Pull request [#9409](https://github.com/ruby/rubygems/pull/9409) by BurdetteLamar
+
+
+## Bundler Release Notes
+
+
+### Enhancements:
+
+* Check the git version only **once** per `bundle install`. Pull request [#9406](https://github.com/ruby/rubygems/pull/9406) by Edouard-chin
+* Normalize the number of workers when performing parallel operations. Pull request [#9400](https://github.com/ruby/rubygems/pull/9400) by Edouard-chin
+* Add exponential backoff to bundler retries. Pull request [#9163](https://github.com/ruby/rubygems/pull/9163) by ChrisBr
+* Introduce a priority queue. Pull request [#9389](https://github.com/ruby/rubygems/pull/9389) by Edouard-chin
+* Split the download and install process of a gem. Pull request [#9381](https://github.com/ruby/rubygems/pull/9381) by Edouard-chin
+
+### Bug fixes:
+
+* Retry git fetch without --depth for dumb HTTP transport. Pull request [#9405](https://github.com/ruby/rubygems/pull/9405) by hsbt
+
+
+## Manual Installation
+
+To install RubyGems by hand see the [Download RubyGems][download] page.
+
+SHA256 Checksums:
+
+* rubygems-4.0.9.tgz  
+  39b1e2c878946e420116c3c26e4e708c0ddbdf7cd4a13c48dd0fc0774c7add8d
+* rubygems-4.0.9.zip  
+  d77dfd4baabcdc5b0a268f79332239bbbe2647f78d40778c243beace61d856a6
+* rubygems-update-4.0.9.gem  
+  e1c0b84abaf481a4e0553d666986156090399afcc099aa18cac6fabbddc45514
+
+
+[download]: https://rubygems.org/pages/download
+