wp-includes/update.php:1029Determines whether core should be updated.
function _maybe_update_core() { $current = get_site_transient( 'update_core' ); if ( isset( $current->last_checked, $current->version_checked ) && 12 * HOUR_IN_SECONDS > ( time() - $current->last_checked ) && wp_get_wp_version() === $current->version_checked ) { return; } wp_version_check();}Introduced in 2.8.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/update.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.