Bump pg versions, add PG15

Author: eaydingol

circleci/images/Makefile

@@ -18,6 +18,8 @@ STYLE_CHECKER_TOOLS_VERSION=0.8.33
 
 # Upgrade tests for the PG major versions from PG_VERSIONS file 
 CITUS_UPGRADE_PG_VERSIONS=$(shell head -n2 PG_VERSIONS|cut -c 6-|tr '\n' ' ')
+
+CITUS_UPGRADE_VERSIONS_15=v12.1.10
 # 12.1.10 is the latest release of Citus 12 when the test is expanded to cover Citus 12
 CITUS_UPGRADE_VERSIONS_16=v12.1.10
 # Latest minor version of Citus 13

circleci/images/PG_VERSIONS

@@ -1,3 +1,3 @@
-PG16=16.11
-PG17=17.7
-PG18=18.1
+PG15=15.17
+PG16=16.13
+PG17=17.9