[TASK] Use local variable in CleanUpLocalProcessedFilesCommand

With recent changes in phpstan/phpstan, it seems the possible return
value of methods is not set in stone anymore, allowing detection
of possible issues in the code.

This change uses a local method variable for the method return
value of `isVerbose()` and uses this instead of several method calls.

Resolves: #100941
Releases: main, 12.4
Change-Id: If4a91d544e43b03279711dd8d5fbbb12c349566f
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/79127
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: core-ci <typo3@b13.com>

typo3/sysext/lowlevel/Classes/Command/CleanUpLocalProcessedFilesCommand.php

@@ -138,7 +138,8 @@ protected function execute(InputInterface $input, OutputInterface $output): int
 
     protected function deleteFile(InputInterface $input, OutputInterface $output, array $files): array
     {
-        if (!$output->isVerbose()) {
+        $isVerbose = $output->isVerbose();
+        if (!$isVerbose) {
             $io = new SymfonyStyle($input, $output);
             $progressBar = $io->createProgressBar(count($files));
         }
@@ -149,10 +150,10 @@ protected function deleteFile(InputInterface $input, OutputInterface $output, ar
             $path = PathUtility::stripPathSitePrefix($file->getRealPath());
             if (unlink($file->getRealPath()) === false) {
                 $error[] = $file;
-                $output->isVerbose() ? $output->writeln('[FILE] Failed to delete ' . $path) : $progressBar->advance();
+                $isVerbose ? $output->writeln('[FILE] Failed to delete ' . $path) : $progressBar->advance();
             } else {
                 $success[] = $file;
-                $output->isVerbose() ? $output->writeln('[FILE] Successfully deleted ' . $path) : $progressBar->advance();
+                $isVerbose ? $output->writeln('[FILE] Successfully deleted ' . $path) : $progressBar->advance();
             }
         }