Merge branch 'php-8.1/fix-deprecation-notice' of https://github.com/jrfnl/PHP_CodeSniffer

Author: gsherwood

src/Ruleset.php

@@ -726,7 +726,7 @@ private function expandRulesetReference($ref, $rulesetDir, $depth=0)
         } else {
             // See if this is a whole standard being referenced.
             $path = Util\Standards::getInstalledStandardPath($ref);
-            if (Util\Common::isPharFile($path) === true && strpos($path, 'ruleset.xml') === false) {
+            if ($path !== null && Util\Common::isPharFile($path) === true && strpos($path, 'ruleset.xml') === false) {
                 // If the ruleset exists inside the phar file, use it.
                 if (file_exists($path.DIRECTORY_SEPARATOR.'ruleset.xml') === true) {
                     $path .= DIRECTORY_SEPARATOR.'ruleset.xml';