fix: add files and group properties to HTMLInputAttributes (#15492)

Fixes #14579
Although this isn't 100% correct because there's no `group` attribute, there's no better way to make people have components' props just be `HTMLInputAttributes` and allow them to reference `group`

.changeset/plenty-bats-lay.md

@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: add `files` and `group` to HTMLInputAttributes in elements.d.ts

packages/svelte/elements.d.ts

@@ -1076,6 +1076,7 @@ export interface HTMLInputAttributes extends HTMLAttributes<HTMLInputElement> {
 	checked?: boolean | undefined | null;
 	dirname?: string | undefined | null;
 	disabled?: boolean | undefined | null;
+	files?: FileList | undefined | null;
 	form?: string | undefined | null;
 	formaction?: string | undefined | null;
 	formenctype?:
@@ -1087,6 +1088,7 @@ export interface HTMLInputAttributes extends HTMLAttributes<HTMLInputElement> {
 	formmethod?: 'dialog' | 'get' | 'post' | 'DIALOG' | 'GET' | 'POST' | undefined | null;
 	formnovalidate?: boolean | undefined | null;
 	formtarget?: string | undefined | null;
+	group?: any | undefined | null;
 	height?: number | string | undefined | null;
 	indeterminate?: boolean | undefined | null;
 	list?: string | undefined | null;