PHP 8.5 | Tokenizer/PHP: fix "Using null as an array offset" deprecation

If an attribute is unclosed (missing the closing `]` bracket), the `PHP::findCloser()` returns `null`, which will lead to the PHP 8.5 deprecation notice.
This can only occur during live coding or when a file has a parse error, but PHPCS should handle that situation gracefully.

Fixed now.

This change is already covered via the existing tests.

Author: jrfnl

src/Tokenizers/PHP.php

@@ -1468,16 +1468,18 @@ protected function tokenize($string)
                 $newToken['type']    = 'T_ATTRIBUTE';
                 $newToken['content'] = '#[';
                 $finalTokens[$newStackPtr] = $newToken;
+                $newStackPtr++;
 
-                $tokens[$bracketCloser]    = [];
-                $tokens[$bracketCloser][0] = T_ATTRIBUTE_END;
-                $tokens[$bracketCloser][1] = ']';
+                if ($bracketCloser !== null) {
+                    $tokens[$bracketCloser]    = [];
+                    $tokens[$bracketCloser][0] = T_ATTRIBUTE_END;
+                    $tokens[$bracketCloser][1] = ']';
 
-                if (PHP_CODESNIFFER_VERBOSITY > 1) {
-                    echo "\t\t* token $bracketCloser changed from T_CLOSE_SQUARE_BRACKET to T_ATTRIBUTE_END".PHP_EOL;
+                    if (PHP_CODESNIFFER_VERBOSITY > 1) {
+                        echo "\t\t* token $bracketCloser changed from T_CLOSE_SQUARE_BRACKET to T_ATTRIBUTE_END".PHP_EOL;
+                    }
                 }
 
-                $newStackPtr++;
                 continue;
             }//end if