package/postgresql: bump version to 16.6
Release notes: https://www.postgresql.org/docs/release/16.6/
Note: this minor version bump fixes a bug introduced in postgresql
security bump to 16.5 fixing CVE-2024-10978.
Signed-off-by: Maxim Kochetkov <fido_max@inbox.ru>
[Julien: add note in commit log]
Signed-off-by: Julien Olivain <ju.o@free.fr>