chore: Set postgres version to 15 for tests

Author: clepski

repository-postgresql/src/test/java/org/lfenergy/compas/scl/data/repository/postgresql/PostgreSQLServerJUnitExtension.java

@@ -35,6 +35,7 @@ public void beforeAll(final ExtensionContext context) throws Exception {
         lock.lock();
         if (pg == null) {
             pg = EmbeddedPostgres.builder()
+                    .setTag("15-alpine")
                     .start();
 
             // We will also run Flyway to upgrade the database.