dp-input slot onInput handler not updating model value in v12.1.0

[kouts]

Describe the bug
When using the dp-input slot with a custom input element, calling the exposed onInput function no longer updates the model value in version 12.1.0. This is a regression from version 12.0.5 where the same code works correctly.

To Reproduce
Steps to reproduce the behavior:

• Use VueDatePicker with the dp-input slot
• Provide a custom input element
• Call the exposed onInput function when the input value changes
• Type a valid date in the input field

<template>
  <VueDatePicker 
    v-model="date" 
    model-type="yyyy-MM-dd" 
    :formats="{ input: 'dd-MMM-yyyy' }" 
    :auto-apply="true"
  >
    <template #dp-input="{ value, onInput, onClear }">
      <input 
        type="text" 
        :value="value" 
        @input="handleInput($event, onInput, onClear)" 
      />
    </template>
  </VueDatePicker>
  <div>Model value: {{ date }}</div>
</template>

<script setup lang="ts">
import { ref } from 'vue';
import { VueDatePicker } from '@vuepic/vue-datepicker';
import '@vuepic/vue-datepicker/dist/main.css';

const date = ref();

const handleInput = (e: Event, onInputFn: (e: Event) => void, onClearFn: (e: Event) => void) => {
  if (e.target instanceof HTMLInputElement && e.target.value === '') {
    onClearFn(e);
    return;
  }
  onInputFn(e);
};
</script>

Expected Behavior
When typing a valid date (e.g., "18-Dec-2025") in the custom input and the onInput function is called:
The date should be parsed according to the formats.input format
The model value should be updated to the parsed date in modelType format (e.g., "2025-12-18")
This works correctly in v12.0.5.

Stackblitz Links
v12.0.5 (Working): https://stackblitz.com/edit/github-bgfv7iv5-cb6jnnet?file=src%2Fviews%2FHome.vue
v12.1.0 (Broken): https://stackblitz.com/edit/github-bgfv7iv5-9nahr6kn?file=src%2Fviews%2FHome.vue

Video

firefox_Ngts2i2An8.mp4