[opentelemetry-php-instrumentation] PHP8.2 support registering hooks after a function was already executed

[Nevay]

PHP ^8.2 allows manipulation of observers at runtime php/php-src#9062.

Should allow us to remove the limitation that hooks must be registered before a function is first executed. https://github.com/open-telemetry/opentelemetry-php-instrumentation?tab=readme-ov-file#caveats

Hooks must be registered before a function is first executed. You may encounter race conditions where the composer autoloader runs code that uses functions you wish to hook prior to the hooks being registered.

[brettmc]

ref: #1278
The feature is available in PHP from 8.2.0