[BUGFIX] Correctly cast folder's 'mtime' and 'ctime' as integer

When opening the "tile view" in the backend, third party FAL adapters
may not correctly return 'mtime' and 'ctime' as integers.
This already is fixed in the main branch but can occur in TYPO3 12 LTS
as well, therefore relevant changes are picked from #101469.

Resolves: #103495
Related: #101469
Releases: 12.4
Change-Id: Ibdcf878da63ff0c79dd1dba8ac28f6f7f68e7a0e
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/83616
Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Sybille Peters <sypets@gmx.de>
Reviewed-by: Simon Schaufelberger <simonschaufi+typo3@gmail.com>
Tested-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Tested-by: Simon Schaufelberger <simonschaufi+typo3@gmail.com>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>

typo3/sysext/core/Classes/Resource/Folder.php

@@ -554,7 +554,7 @@ public function getParentFolder()
      */
     public function getModificationTime()
     {
-        return $this->storage->getFolderInfo($this)['mtime'];
+        return (int)$this->storage->getFolderInfo($this)['mtime'];
     }
 
     /**
@@ -564,6 +564,6 @@ public function getModificationTime()
      */
     public function getCreationTime()
     {
-        return $this->storage->getFolderInfo($this)['ctime'];
+        return (int)$this->storage->getFolderInfo($this)['ctime'];
     }
 }