[php-src] PR #23634: Persist the `pear/install-pear-nozlib.phar` file

Pull Request: https://github.com/php/php-src/pull/23634 Author: DanielEScherzer Rather than downloading it as part of the makedist script, add the script to the project's version control. The installation instructions are updated to indicate that the needed phar script is always present, and the only thing needed is to become the superuser and run make install-pear. The phar is currently marked as binary in the git attributes since it is not entirely text, it is committed as-is from the pear server and can be cleaned up in future commits. This also fixes the installation process when previously the installation would try to fallback to the fetch.php helper - it seems that the https stream wrapper is not included in PHP by default. Now that the phar is committed to version control, the fetch.php helper script is no longer needed. After this patch, ./configure --with-pear --enable-xml allows installing pear with make without additional manual actions. Also includes a cherry-pick of #14216 to update the instructions in pear/install-pear.txt.