[Caching] Fix cache consecutive run rector with --dry-run (#3060)

* [Caching] Fix cache consecutive run rector with --dry-run

* resolve fiel path cache key

* Final touch: fallback when realpath is false

* Really final touch: phpstan

* Final touch: move resolve path to separate method to be used in hashFile()

packages/Caching/Detector/ChangedFilesDetector.php

@@ -90,14 +90,25 @@ public function setFirstResolvedConfigFileInfo(string $filePath): void
         $this->storeConfigurationDataHash($filePath, $configHash);
     }
 
+    private function resolvePath(string $filePath): string
+    {
+        $realPath = realpath($filePath);
+
+        if ($realPath === false) {
+            return $filePath;
+        }
+
+        return $realPath;
+    }
+
     private function getFilePathCacheKey(string $filePath): string
     {
-        return sha1($filePath);
+        return sha1($this->resolvePath($filePath));
     }
 
     private function hashFile(string $filePath): string
     {
-        return (string) sha1_file($filePath);
+        return (string) sha1_file($this->resolvePath($filePath));
     }
 
     private function storeConfigurationDataHash(string $filePath, string $configurationHash): void