PDK Vanagon 2.6.1.0

This release marks version 2.6.1.0 of the pdk-vanagon project.

Here are some things that have changed:

• (CONT-507) Add OSX 12 platform by @GSPatton in #309
• (CONT-513) Add Ubuntu 22.04 platform file by @GSPatton in #310
• Fix Ubuntu 22.04 platform filename by @GSPatton in #311

Full Changelog: 2.6.0.0...2.6.1.0