On September 14th we announced the deprecation of the STK bundle.
https://forum.magnolia-cms.com/forum/thread.html?threadId=63eb7505-2b9c-4fd9-9d0d-3dfcce1ba5f8&page=1
It was stated that we

• We no longer provide bundles that include STK. You can still get the STK modules from Nexus for your own bundle. (1)

We should therefore remove both STK related modules from ee-packs:

• magnolia-enterprise-pro-stk-bundle
• magnolia-enterprise-pro-stk-webapp

We should however maintain related version in dependency management as we ourselves are still using STK in test-webapp.