Upgrade pg-types to 4.0.2 for performance improvements

[cesco69]

pg-types 4.0.2 include performance improvements from brianc/node-pg-types#148

[sisou]

This will also fix a Node 20 depreciation warning: DeprecationWarning: Buffer() is deprecated due to security and usability issues.

new Buffer() was used in an old version of postgres-bytea, which is depended on by pg-types. The buffer usage was updated in bendrucker/postgres-bytea@2317d6d, which went into release 2.0.0, which pg-types was updated to only in version 3.0.0 (brianc/node-pg-types@c605c7c).

[brianc]

I want to do this, but pg-types upgrading to 4.x is a breaking change for node-postgres (date handling is different). I want to make some other changes & bundle it all up w/ a 9.0 release for pg so its gonna take some time...but its on my list.