Fix phpunit workaround syntax

src/Composer/Installer/BinaryInstaller.php

@@ -267,8 +267,7 @@ class BinaryInstaller
             }
             // Add workaround for PHPUnit process isolation on PHPUnit 6+
             if ($this->filesystem->normalizePath($bin) === $this->filesystem->normalizePath($this->vendorDir.'/phpunit/phpunit/phpunit')) {
-                $autoloadPathCode .= '$GLOBALS[\'__PHPUNIT_ISOLATION_EXCLUDE_LIST\'] = [realpath('.$binPathExported.')];'."\n"
-                    .'$GLOBALS[\'__PHPUNIT_ISOLATION_BLACKLIST\'] = [realpath('.$binPathExported.')];'."\n";
+                $autoloadPathCode .= '$GLOBALS[\'__PHPUNIT_ISOLATION_EXCLUDE_LIST\'] = $GLOBALS[\'__PHPUNIT_ISOLATION_BLACKLIST\'] = array(realpath('.$binPathExported.'));'."\n";
             }
             if (trim($match[0]) !== '<?php') {
                 $streamHint = ' using a stream wrapper to prevent the shebang from being output on PHP<8'."\n *";