Bump Citus Version to 12.1.6 (#7744)

Bump Citus Version to 12.1.6

configure.ac

@@ -5,7 +5,7 @@
 # everyone needing autoconf installed, the resulting files are checked
 # into the SCM.
 
-AC_INIT([Citus], [12.1.5])
+AC_INIT([Citus], [12.1.6])
 AC_COPYRIGHT([Copyright (c) Citus Data, Inc.])
 
 # we'll need sed and awk for some of the version commands

src/test/regress/expected/multi_extension.out

@@ -1413,7 +1413,7 @@ DROP TABLE multi_extension.prev_objects, multi_extension.extension_diff;
 SHOW citus.version;
  citus.version
 ---------------------------------------------------------------------
- 12.1.5
+ 12.1.6
 (1 row)
 
 -- ensure no unexpected objects were created outside pg_catalog