Revert "Add reno for Tempest v15.0.0"

We cannot add a new reno into the existing tag, so we need to
revert the patch.

This reverts commit 4e9c1dcf8f5c7f743e4ad98ae9f095b1078a691f.

Change-Id: I7554cdcd7968bde2ce0924dcbac5f349ae230935
1 file changed