databases/postgresql??-*: Update to latest versions

Update to 18.6, 17.11, 16.15, 15.19 and 14.24.

This release fixes 28 security vulnerabilities and over 110 bugs
reported over the last several months.

Welcome postgresql19 to the ports tree with 19-beta3.

Note: PostgreSQL 18.5 was skipped due to a regression; the fix
version is 18.6.

PostgreSQL 14 will stop receiving fixes on 2026-11-12.

Changes: https://www.postgresql.org/about/news/postgresql-186-1711-1615-1519-1424-and-19-beta-3-released-3365/
Security: 05d311bc-9991-11f1-bc50-6cc21735f730