Add scratch file for a v6 release process undo stack

v6_undo_stack.markdown

@@ -0,0 +1,17 @@
+# Temporary changes for v6
+
+This is a temporary file, containing changes done to release process for v6,
+that need to be reverted back.
+
+It's a file in the repository to allow for easier tracking of the status
+of things among the broader community, and to allow everyone to add/delete
+things they believe should be in here.
+
+The file is scheduled for deletion by the actual release of `v6` and subsequent
+rollback of the changes.
+
+## Stack
+
+* Revert changes to homebrew PR push (`.github/workflows/release-packages.yaml`)
+* Revert changes to docker image push (`.github/workflows/releas-packages.yaml`)
+* Remove marking of release as `prerelease` (`.github/workflows/regular-release.yaml`)