qt5: update postgresql variants

[dgilman]

Description

I was able to build the qt5-psql-plugin against postgresql16 successfully and confirmed the plugin binary was correctly linked against postgresql16. However, I didn't test any functionality. I also tried to build qt57 to test the plugin but couldn't get the qt base package to build at all. Maybe a consequence of the new xcode?

Type(s)

• bugfix
• enhancement
• security fix

Tested on

macOS 14.6.1 23G93 x86_64
Xcode 16.0 16A242d

Verification

Have you

• followed our Commit Message Guidelines?
• squashed and minimized your commits?
• checked that there aren't other open pull requests for the same change?
• referenced existing tickets on Trac with full URL in commit message?
• checked your Portfile with port lint --nitpick?
• tried existing tests with sudo port test?
• tried a full install with sudo port -vst install?
• tested basic functionality of all binary files?
• checked that the Portfile's most important variants haven't been broken?

[macportsbot]

Notifying maintainers:
@MarcusCalhoun-Lopez for port qt5, qt511, qt513, qt53, qt55, qt56, qt57, qt58, qt59.