refactor: Fix some easy psalm issues in Files

Signed-off-by: Carl Schwan <carl.schwan@nextcloud.com>

build/psalm-baseline.xml

@@ -3614,33 +3614,6 @@
       <code><![CDATA[$stat === false]]></code>
     </TypeDoesNotContainType>
   </file>
-  <file src="lib/private/Files/Storage/LocalRootStorage.php">
-    <NoInterfaceProperties>
-      <code><![CDATA[$storage->scanner]]></code>
-      <code><![CDATA[$storage->scanner]]></code>
-    </NoInterfaceProperties>
-  </file>
-  <file src="lib/private/Files/Storage/Wrapper/Encoding.php">
-    <UndefinedInterfaceMethod>
-      <code><![CDATA[$this->namesCache]]></code>
-      <code><![CDATA[$this->namesCache]]></code>
-      <code><![CDATA[$this->namesCache]]></code>
-      <code><![CDATA[$this->namesCache]]></code>
-      <code><![CDATA[$this->namesCache]]></code>
-      <code><![CDATA[$this->namesCache]]></code>
-      <code><![CDATA[$this->namesCache]]></code>
-      <code><![CDATA[$this->namesCache]]></code>
-      <code><![CDATA[$this->namesCache]]></code>
-      <code><![CDATA[$this->namesCache]]></code>
-      <code><![CDATA[$this->namesCache]]></code>
-      <code><![CDATA[$this->namesCache]]></code>
-      <code><![CDATA[$this->namesCache]]></code>
-      <code><![CDATA[$this->namesCache]]></code>
-      <code><![CDATA[$this->namesCache]]></code>
-      <code><![CDATA[$this->namesCache]]></code>
-      <code><![CDATA[$this->namesCache]]></code>
-    </UndefinedInterfaceMethod>
-  </file>
   <file src="lib/private/Files/Storage/Wrapper/Encryption.php">
     <InvalidReturnStatement>
       <code><![CDATA[$result]]></code>

lib/private/Files/Storage/LocalRootStorage.php

@@ -17,6 +17,7 @@ class LocalRootStorage extends Local {
 		if (!$storage) {
 			$storage = $this;
 		}
+		/** @var Local $storage */
 		return $storage->scanner ?? ($storage->scanner = new LocalRootScanner($storage));
 	}
 }

lib/private/Files/Storage/Wrapper/Encoding.php

@@ -11,7 +11,6 @@ use OC\Files\Filesystem;
 use OCP\Cache\CappedMemoryCache;
 use OCP\Files\Cache\IScanner;
 use OCP\Files\Storage\IStorage;
-use OCP\ICache;
 
 /**
  * Encoding wrapper that deals with file names that use unsupported encodings like NFD.
@@ -20,10 +19,7 @@ use OCP\ICache;
  * the actual given name and then try its NFD form.
  */
 class Encoding extends Wrapper {
-	/**
-	 * @var ICache
-	 */
-	private $namesCache;
+	private CappedMemoryCache $namesCache;
 
 	/**
 	 * @param array $parameters