Fix clicking <Label /> opens <input type="file"> (#3707)

This PR fixes an issue where the `<Label>` component didn't open the
`<input type="file">` when clicking it.

For native elements, the `Label` component already renders a native
`<label>` behind the scenes. Some native elements like `<input
type="checkbox">` immediately change the state of the element whereas
some other elements don't such as `<select></select>` you just get the
focus.

However, `<input type="file">` should also immediately open the file
picker when clicking the label and this was not the case. This PR fixes
that.

Since we are already using a native `<label>` _and_ linking the
`<label>` with its `<input type="file">` performing a `.click()` is
allowed.

Fixes: #3680


## Test plan

You can play with it here:
https://headlessui-react-git-fix-issue-3680-tailwindlabs.vercel.app/combinations/form

This video shows how it behaves now:


https://github.com/user-attachments/assets/26467f83-d91d-4a79-98f9-dd91214ea037

playgrounds/react/pages/combinations/form.tsx

@@ -1,4 +1,4 @@
-import { Combobox, Listbox, RadioGroup, Switch } from '@headlessui/react'
+import { Combobox, Field, Input, Label, Listbox, RadioGroup, Switch } from '@headlessui/react'
 import { useState } from 'react'
 import { Button } from '../../components/button'
 import { classNames } from '../../utils/class-names'
@@ -332,6 +332,24 @@ export default function App() {
               </Combobox>
             </div>
           </Section>
+          <Section title="Default form controls">
+            <Field className="flex flex-col p-1">
+              <Label>Label for {'<Input type="text">'}</Label>
+              <Input type="text" />
+            </Field>
+            <Field className="flex flex-col p-1">
+              <Label>Label for {'<Input type="checkbox">'}</Label>
+              <Input type="checkbox" />
+            </Field>
+            <Field className="flex flex-col p-1">
+              <Label>Label for {'<Input type="radio">'}</Label>
+              <Input type="radio" />
+            </Field>
+            <Field className="flex flex-col p-1">
+              <Label>Label for {'<Input type="file">'}</Label>
+              <Input type="file" />
+            </Field>
+          </Section>
         </div>
 
         <div className="space-x-4">