refactor(runtime-vapor): pass vapor slot fallback directly to `renderSlot`

packages/runtime-core/src/helpers/renderSlot.ts

@@ -130,7 +130,7 @@ export function ensureValidVNode(
     : null
 }
 
-export function ensureVaporSlotFallback(
+function ensureVaporSlotFallback(
   vnodes: VNodeArrayChildren | null | undefined,
   fallback?: () => VNodeArrayChildren,
 ): void {

packages/runtime-core/src/index.ts

@@ -608,10 +608,6 @@ export { setRef } from './rendererTemplateRef'
  * @internal
  */
 export { type VNodeNormalizedRef, normalizeRef } from './vnode'
-/**
- * @internal
- */
-export { ensureVaporSlotFallback } from './helpers/renderSlot'
 /**
  * @internal
  */

packages/runtime-vapor/src/vdomInterop.ts

@@ -21,7 +21,6 @@ import {
   currentInstance,
   ensureHydrationRenderer,
   ensureRenderer,
-  ensureVaporSlotFallback,
   isEmitListener,
   isKeepAlive,
   isRef,
@@ -464,12 +463,10 @@ function renderVDOMSlot(
           slotsRef.value,
           isFunction(name) ? name() : name,
           props,
+          fallback as any,
         )
 
         let children = vnode.children as any[]
-        // handle forwarded vapor slot without its own fallback
-        // use the fallback provided by the slot outlet
-        ensureVaporSlotFallback(children, fallback as any)
         isValidSlot = children.length > 0
       }