fix: prevent nodes from being unintentionally deleted by pressing the backspace key. (#21023)

web/app/components/base/prompt-editor/plugins/component-picker-block/index.tsx

                         isSupportFileVar={isSupportFileVar}
                         onClose={handleClose}
                         onBlur={handleClose}
+                        autoFocus={false}
                       />
                     </div>
                   )

web/app/components/workflow/hooks/use-shortcuts.ts

     return !showFeaturesPanel && !isEventTargetInputArea(e.target as HTMLElement)
   }, [workflowStore])
 
-  useKeyPress(['delete', 'backspace'], (e) => {
+  useKeyPress(['delete'], (e) => {
     if (shouldHandleShortcut(e)) {
       e.preventDefault()
       handleNodesDelete()

web/app/components/workflow/nodes/_base/components/variable/var-reference-vars.tsx

   maxHeightClass?: string
   onClose?: () => void
   onBlur?: () => void
+  autoFocus?: boolean
 }
 const VarReferenceVars: FC<Props> = ({
   hideSearch,
   maxHeightClass,
   onClose,
   onBlur,
+  autoFocus = true,
 }) => {
   const { t } = useTranslation()
   const [searchText, setSearchText] = useState('')
                 onKeyDown={handleKeyDown}
                 onClear={() => setSearchText('')}
                 onBlur={onBlur}
-                autoFocus
+                autoFocus={autoFocus}
               />
             </div>
             <div className='relative left-[-4px] h-[0.5px] bg-black/5' style={{