update to postgres 18 with nc33

[szaimen]

• needs tests in nextcloud/server feat: Update supported PostgreSQL versions server#56155
• update docs: feat: Support postgres 18 but drop postgres 13 documentation#13888
• wait for 18.1
• wait for nc 33 update
• update in aio (need to update PG_DATA to store in the root of /var/lib/postgres again)

Link to #5364 for reference

[morph027]

FYI: 18.1 has been released last week: https://www.postgresql.org/docs/release/18.1/