fix: allow unclosed single quotes in php-template (fixes #4152)

[KJyang-0114]

Description

Fixes issue #4152 where a single apostrophe (unclosed quote) in php-template breaks highlighting for everything after it.

Problem

In php-template, an unclosed single quote like causes the entire remainder of the document to not be highlighted correctly. The issue does not occur in regular PHP mode.

Solution

Removed the skip: true property from the inherited APOS_STRING_MODE and QUOTE_STRING_MODE in php-template.js. This allows the parser to handle unclosed quotes more gracefully without breaking subsequent highlighting.

Testing

Added a test case in test/markup/php-template-apostrophe/default.txt that reproduces the issue from the bug report.

Reproduction

<?php
// This won\'t be highlighted unless there is another 
// single apostrophe later.
?>
<p>Some HTML <?= '\code' ?></p>