Deprecated function get_system_context() still used in index.php

[saidisalem]

File: index.php
Line: 57
Affected Moodle version: 4.4+

The deprecated function get_system_context() is still being used in index.php with a version check:

if ($CFG->branch >= 25) { // Moodle 2.5+.
    $context = context_system::instance();
} else {
    $context = get_system_context();
}

This condition is now outdated and unsafe:

• Moodle 2.5 is no longer supported.
• get_system_context() has been entirely removed, and will now throw a fatal exception in Moodle 4.4+.

Suggested fix
Simplify the conditional logic by removing the legacy fallback:
$context = context_system::instance();
No version check is required anymore.