Revert "Mention bug in PostgreSQL 18 for GIN index build"

This reverts commit 5555472.

Has been fixed in PostgreSQL 18.1

Author: joto

_manual-v2/03-database.md

@@ -117,7 +117,7 @@ value in the third column is the default set by PostgreSQL 17.
 | -------------------------------------------------------------------------------------------------------------------------------- | --------------- | ------------- | ------ |
 | [shared_buffers](https://www.postgresql.org/docs/current/runtime-config-resource.html#GUC-SHARED-BUFFERS)                        | 1GB             | 128MB         | Lower than typical PostgreSQL recommendations to give osm2pgsql priority to RAM. |
 | [work_mem](https://www.postgresql.org/docs/current/runtime-config-resource.html#GUC-WORK-MEM)                                    | 50MB            | 4MB           | |
-| [maintenance_work_mem](https://www.postgresql.org/docs/current/runtime-config-resource.html#GUC-MAINTENANCE-WORK-MEM)            | 10GB            | 64MB          | Improves `CREATE INDEX`. (The maximum setting on Windows is 1GByte. Do not set this any higher than 256 MB with PostgreSQL 18, because of [a bug in that version](https://www.linkedin.com/pulse/postgis-day-2025-postgres-18-builds-gin-indexes-3x-fast-greg-smith-7m3ze).) |
+| [maintenance_work_mem](https://www.postgresql.org/docs/current/runtime-config-resource.html#GUC-MAINTENANCE-WORK-MEM)            | 10GB            | 64MB          | Improves `CREATE INDEX`. (The maximum setting on Windows is 1GByte.) |
 | [autovacuum_work_mem](https://www.postgresql.org/docs/current/runtime-config-resource.html#GUC-AUTOVACUUM-WORK-MEM)              | 2GB             | -1            | -1 uses `maintenance_work_mem` |
 | [wal_level](https://www.postgresql.org/docs/current/runtime-config-wal.html#GUC-WAL-LEVEL)                                       | minimal         | replica       | Reduces WAL activity if replication is not required during data load.  Must also set `max_wal_senders=0`. |
 | [checkpoint_timeout](https://www.postgresql.org/docs/current/runtime-config-wal.html#GUC-CHECKPOINT-TIMEOUT)                     | 60min           | 5min          | Increasing this value reduces time-based checkpoints and increases time to restore from PITR |