hard code postgres versions

Author: naisila

packaging_automation/test_citus_package.py

@@ -84,7 +84,8 @@ def get_postgres_versions_from_matrix_file(project_version: str) -> List[str]:
 
     platform = args.os_release
 
-    postgres_versions = get_postgres_versions_from_matrix_file(args.project_version)
+    # postgres_versions = get_postgres_versions_from_matrix_file(args.project_version)
+    postgres_versions = ["15", "16"]
 
     print(f"This version of Citus supports following pg versions: {postgres_versions}")