Abandon same-instances-scheduling backlog spec

Scrubbing the backlog directory.

This spec has been here since 2015.

The original authors should feel free to modify or downvote this commit
if the spec should continue to be considered for implementation now or
in the future.

Change-Id: I6e243b34dbe82aab2f91887a8a8f46e44d10afbb

specs/abandoned/same-instances-scheduling.rst

@@ -8,6 +8,9 @@
 Sort instances if possible inside an host aggregate
 ===================================================
 
+.. note:: This spec was abandoned by efried on account of having been
+          sitting in the backlog directory since 2015.
+
 https://blueprints.launchpad.net/nova/+spec/same-instances-scheduling
 
 Nova should allow sorting instances based on preferences without
@@ -132,3 +135,5 @@ None
      - Description
    * - Liberty
      - Introduced
+   * - Train
+     - Abandoned

specs/backlog/redirects

@@ -1 +1,2 @@
 approved/parallel-scheduler.rst ../../abandoned/parallel-scheduler.rst
+approved/same-instances-scheduling.rst ../../abandoned/same-instances-scheduling.rst