fix: make lsphp opcache conditional — not available for PHP 8.5

lsphp85-opcache doesn't exist in the LiteSpeed repo (opcache is
bundled in the base lsphp85 package). Only add opcache as a
separate package for PHP 7.4-8.4.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

wo/core/variables.py

@@ -147,9 +147,13 @@ class WOVar():
         short_ver = version_number.replace('.', '')
         wo_module = ["common", "curl", "igbinary",
                      "imagick", "intl", "memcached", "msgpack",
-                     "mysql", "opcache", "pear", "redis",
+                     "mysql", "pear", "redis",
                      "snmp", "sqlite3", "tidy"]
 
+        # opcache is a separate package only on older PHP versions
+        if version_number in ('7.4', '8.0', '8.1', '8.2', '8.3', '8.4'):
+            wo_module.append("opcache")
+
         # lsphp packages: lsphpXX, lsphpXX-common, lsphpXX-curl, etc.
         php_modules = ["lsphp{0}".format(short_ver)]
         php_modules.extend(["lsphp{0}-{1}".format(short_ver, module) for module in wo_module])