General: Only override `$table_prefix` if not defined

Only set the variable $table_prefix, if set before (e.g. via some kind of custom bootstrapper).

To use ??= operator we need >= php8.4, but happily referring to your documentation, this is already the current minimum requirement :D
​https://wordpress.org/about/requirements/
-> bumped version in composer.json

Trac:
https://core.trac.wordpress.org/ticket/63627

Hi @ninos-ego,

Could you expand on the reasoning for the change? What are you attempting to achieve, what problem does this solve? etc

Sorry for the late response...

I'm using some kind of wordpress bootstrapper to preload some environment configs before initializing wordpress, e.g. database, url, proxy, settings, ... Useful at least for containerized environments.

My current workaround is writing following line of code before including wp-settings.php:

$table_prefix = $GLOBALS['table_prefix'];

Its not much line of codes, but I want to get rid of it (object-oriented coding). My patch will not break anything, it just gives a bit more flexibility initializing wordpress :-)

In 61250: