Update .NET SDK versions in release notes

Author: victorisr

release-notes/8.0/8.0.12/8.0.12.md

@@ -3,7 +3,6 @@
 The .NET 8.0.12 and .NET SDK 8.0.405 releases are available for download. The latest 8.0 release is always listed at [.NET 8.0 Releases](../README.md).
 
 8.0 SDKs that are included in 8.0.12 runtimes:
-* [8.0.405][8.0.405]
 * [8.0.112][8.0.112]
 * [8.0.308][8.0.308]