replace google material icons with phosphor icons

src/lib/Checkbox.svelte

@@ -7,6 +7,7 @@
 	import { validate } from '@svelte-toolkit/validate';
 	import { generateIdentifier } from './util';
 	import type { ClassValue } from 'svelte/elements';
+	import { Check, Minus } from 'phosphor-svelte';
 
 	interface Props {
 		name?: string;
@@ -31,6 +32,7 @@
 	let id = $derived(generateIdentifier('checkbox', name));
 
 	let valid = $state(true);
+	let Icon = $derived(value === 'indeterminate' ? Minus : value ? Check : undefined);
 </script>
 
 <div class={['flex items-center', classValue]}>
@@ -69,10 +71,8 @@
 			onchange?.(value);
 		}}
 	>
-		{#if value === 'indeterminate'}
-			<span class="material-symbols-outlined">remove</span>
-		{:else if value === true}
-			<span class="material-symbols-outlined">check</span>
+		{#if Icon}
+			<Icon weight="bold" size="1.1em"></Icon>
 		{/if}
 	</button>