[php-src] Issue #13710: `rtrim` equal fast to `preg_replace`

Issue: https://github.com/php/php-src/issues/13710 Author: staabm ### Description I am currently doing some micro benchmarks and tried several things to speedup phpunit in some form. one idea I had when looking at a hotpath of a app was to replace ``` $string = (string) preg_replace('#\d+$#', '', $name, -1, $count); ``` with ``` $string = rtrim($name, '0123456789') ``` see ``` mstaab@mst22:/www/www$ hyperfine --warmup 10 'php preg.php' 'php rtrim.php' Benchmark 1: php preg.php Time (mean ± σ): 56.9 ms ± 9.0 ms [User: 30.6 ms, System: 25.7 ms] Range (min … max): 43.8 ms … 80.4 ms 41 runs Benchmark 2: php rtrim.php Time (mean ± σ): 58.7 ms ± 9.2 ms [User: 34.0 ms, System: 24.0 ms] Range (min … max): 43.8 ms … 83.0 ms 46 runs Summary 'php preg.php' ran 1.03 ± 0.23 times faster than 'php rtrim.php' mstaab@mst22:/www/www$ php -v PHP 8.1.27 (cli) (built: Dec 21 2023 20:19:54) (NTS) Copyright (c) The PHP Group Zend Engine v4.1.27, Copyright (c) Zend Technologies ``` ### PHP Version 8.1.27 ### Operating System ubuntu22.04 lts