Fix PHPStan Pro flickering

It was caused by some files being iterated over multiple times, resulting in them always being reported as new.

Author: ondrejmirtes

src/File/FileMonitor.php

@@ -46,7 +46,7 @@ public function initialize(array $filePaths): void
 {
 $finderResult = $this->analyseFileFinder->findFiles($this->analysedPaths);
 $fileHashes = [];
-foreach (array_merge($finderResult->getFiles(), $filePaths, $this->getScannedFiles($finderResult->getFiles())) as $filePath) {
+foreach (array_unique(array_merge($finderResult->getFiles(), $filePaths, $this->getScannedFiles($finderResult->getFiles()))) as $filePath) {
 $fileHashes[$filePath] = $this->getFileHash($filePath);
 }
 
@@ -65,7 +65,8 @@ public function getChanges(): FileMonitorResult
 $newFiles = [];
 $changedFiles = [];
 $deletedFiles = [];
-foreach (array_merge($finderResult->getFiles(), $this->filePaths, $this->getScannedFiles($finderResult->getFiles())) as $filePath) {
+$filePaths = array_unique(array_merge($finderResult->getFiles(), $this->filePaths, $this->getScannedFiles($finderResult->getFiles())));
+foreach ($filePaths as $filePath) {
 if (!array_key_exists($filePath, $oldFileHashes)) {
 $newFiles[] = $filePath;
 $fileHashes[$filePath] = $this->getFileHash($filePath);