[opentelemetry-php-instrumentation] Can't seem to hook namespaced functions.

[bartvanhoutte]

Describe your environment
PHP 8.4

opentelemetry.allow_stack_extension
Off
opentelemetry.attr_hooks_enabled
Off
opentelemetry.attr_post_handler_function
OpenTelemetry\API\Instrumentation\WithSpanHandler::post
opentelemetry.attr_pre_handler_function
OpenTelemetry\API\Instrumentation\WithSpanHandler::pre
opentelemetry.conflicts

opentelemetry.display_warnings
Off
opentelemetry.validate_hook_functions
On

Steps to reproduce
Create a hook for a namespaced function:

        hook(
            class: null,
            function: '\Some\Namespace\hookMe',
            pre: function (...$args) {
                print_r($args);
                return $args;
            },
        );

What is the expected behavior?
A printout of the arguments passed to \Some\Namespace\hookMe.

What is the actual behavior?
Nothing happens

Additional context
This works for functions that are not in a namespace.

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[brettmc]

I'll release the fix soon, but in the meantime you can just remove the leading slash to make it work.