Skip hidden files in backup

We don't need to parse hidden files/directories for backup targets.
This can be very large (in the case of .git directories) and thus
slow when working over NAS.

Fixes https://gitlab.com/kicad/code/kicad/-/issues/18341

common/project/project_archiver.cpp

@@ -214,12 +214,12 @@ bool PROJECT_ARCHIVER::Archive( const wxString& aSrcDir, const wxString& aDestFi
     wxArrayString files;
 
     for( unsigned ii = 0; ii < arrayDim( extensionList ); ii++ )
-        wxDir::GetAllFiles( sourceDir.GetFullPath(), &files, extensionList[ii] );
+        wxDir::GetAllFiles( sourceDir.GetFullPath(), &files, extensionList[ii], wxDIR_FILES | wxDIR_DIRS );
 
     if( aIncludeExtraFiles )
     {
         for( unsigned ii = 0; ii < arrayDim( extraExtensionList ); ii++ )
-            wxDir::GetAllFiles( sourceDir.GetFullPath(), &files, extraExtensionList[ii] );
+            wxDir::GetAllFiles( sourceDir.GetFullPath(), &files, extraExtensionList[ii], wxDIR_FILES | wxDIR_DIRS );
     }
 
     for( unsigned ii = 0; ii < files.GetCount(); ++ii )