Remove unnecessary statement

The casting of `$id` to string inside the second foreach loop in `\Symfony\Component\DependencyInjection\Dumper\PhpDumper::addMethodMap` is redundant, as the variable is not used after the casting inside nor outside the loop (while still in the loop, it gets overriden upon next iteration).

Fixes #33206

src/Symfony/Component/DependencyInjection/Dumper/PhpDumper.php

@@ -1170,7 +1170,6 @@ EOF;
             if (!$id->isDeprecated()) {
                 continue;
             }
-            $id = (string) $id;
             $code .= '            '.$this->doExport($alias).' => '.$this->doExport($this->generateMethodName($alias)).",\n";
         }