debian: Update PostgreSQL version to 15, used in Debian 12

debian/control

@@ -14,10 +14,10 @@ Build-Depends:
   postgresql-all (>= 217~),
   sqitch,
   pgtap,
-  postgresql-13-pg-libphonenumber,
-  postgresql-13-pgtap,
-  postgresql-13-pguri,
-  postgresql-13-vat
+  postgresql-15-pg-libphonenumber,
+  postgresql-15-pgtap,
+  postgresql-15-pguri,
+  postgresql-15-vat
 Standards-Version: 4.6.0
 XS-Go-Import-Path: dev.tandem.ws/tandem/numerus
 Vcs-Browser: https://dev.tandem.ws/tandem/numerus
@@ -52,9 +52,9 @@ Package: numerus-sqitch
 Architecture: all
 Depends:
   ${misc:Depends},
-  postgresql-13-pg-libphonenumber,
-  postgresql-13-pguri,
-  postgresql-13-vat,
+  postgresql-15-pg-libphonenumber,
+  postgresql-15-pguri,
+  postgresql-15-vat,
   sqitch
 Description: Simple invoicing and accounting web application
  A simple web application to keep invoice and accouting records, intended for

debian/rules

@@ -7,4 +7,4 @@ execute_before_dh_auto_build:
 	make
 
 execute_after_dh_auto_test:
-	pg_virtualenv -v 13 make test-deploy
+	pg_virtualenv -v 15 make test-deploy