postgresql: update to version 16.3

postgresql: update to version 16.3

Switch to new major version 16.
Use meson to build for target, however, old autotools-style configure is
needed to clean the source directory before being able to run meson, and
host build of the timezone compiler ('zic') also still requires using the
old build system.

See also https://www.postgresql.org/docs/16/release-16.html

Signed-off-by: Daniel Golle <daniel@makrotopia.org>