fix(gui/macOS): Add required availability checks around typeAndCreator access for NSFileProviderItem wrapper

Signed-off-by: Claudio Cambra <claudio.cambra@nextcloud.com>

Author: claucambra

src/gui/macOS/fileprovideritemmetadata_mac.mm

@@ -72,8 +72,10 @@ QString nsNameComponentsToLocalisedQString(NSPersonNameComponents *const nameCom
     metadata._capabilities = bridgedNsFileProviderItem.capabilities;
     metadata._fileSystemFlags = bridgedNsFileProviderItem.fileSystemFlags;
     metadata._childItemCount = bridgedNsFileProviderItem.childItemCount.unsignedIntegerValue;
-    metadata._typeOsCode = bridgedNsFileProviderItem.typeAndCreator.type;
-    metadata._creatorOsCode = bridgedNsFileProviderItem.typeAndCreator.creator;
+    if (@available(macOS 12.0, *)) {
+        metadata._typeOsCode = bridgedNsFileProviderItem.typeAndCreator.type;
+        metadata._creatorOsCode = bridgedNsFileProviderItem.typeAndCreator.creator;
+    }
     metadata._documentSize = bridgedNsFileProviderItem.documentSize.unsignedLongLongValue;
     metadata._mostRecentVersionDownloaded = bridgedNsFileProviderItem.mostRecentVersionDownloaded;
     metadata._uploading = bridgedNsFileProviderItem.uploading;