initial postgres16 support

pom.xml

@@ -26,7 +26,7 @@
         <packaging.type>war</packaging.type>
 
         <reload4j.version>1.2.18.4</reload4j.version>
-        <flyway.version>9.21.2</flyway.version>
+        <flyway.version>9.22.1</flyway.version>
         <jhove.version>1.20.1</jhove.version>
         <jacoco.version>0.8.7</jacoco.version>
         <poi.version>5.2.1</poi.version>
@@ -790,7 +790,7 @@
                 <skipIntegrationTests>true</skipIntegrationTests>
                 <!-- Once we truly run tests with Testcontainers, this should be switch to "docker", activating ITs -->
                 <packaging.type>docker-build</packaging.type>
-                <postgresql.server.version>13</postgresql.server.version>
+                <postgresql.server.version>16</postgresql.server.version>
 
                 <app.image>gdcc/dataverse:${app.image.tag}</app.image>
                 <app.image.tag>unstable</app.image.tag>

scripts/installer/install.py

@@ -422,9 +422,13 @@
    conn.close()
 
    if int(pg_major_version) >= 15:
+      admin_conn_string = "dbname='"+pgDb+"' user='postgres' password='"+pgAdminPassword+"' host='"+pgHost+"'"
+      conn = psycopg2.connect(admin_conn_string)
+      conn.set_isolation_level(ISOLATION_LEVEL_AUTOCOMMIT)
+      cur = conn.cursor()
       conn_cmd = "GRANT CREATE ON SCHEMA public TO "+pgUser+";"
-      print("PostgreSQL 15 or higher detected. Running " + conn_cmd)
       try:
+         print("PostgreSQL 15 or higher detected. Running " + conn_cmd)
          cur.execute(conn_cmd)
       except:
          if force: