Fix link to blog posts

Due to a missing `s`, a link to the blog archive
for releases was broken.

doc/policy/maintenance.md

@@ -44,7 +44,7 @@ This decision is made on a case-by-case basis.
 
 ## Upgrade recommendations
 
-We encourage everyone to run the [latest stable release](https://about.gitlab.com/blog/categories/release/) to ensure that you can
+We encourage everyone to run the [latest stable release](https://about.gitlab.com/blog/categories/releases/) to ensure that you can
 easily upgrade to the most secure and feature-rich GitLab experience. In order
 to make sure you can easily run the most recent stable release, we are working
 hard to keep the update process simple and reliable.