chore: remove unused `mounting` variable from `select_option` call

packages/svelte/src/internal/client/dom/elements/attributes.js

@@ -491,7 +491,7 @@ export function attribute_effect(
 		var current = set_attributes(element, prev, next, css_hash, skip_warning);
 
 		if (inited && is_select && 'value' in next) {
-			select_option(/** @type {HTMLSelectElement} */ (element), next.value, false);
+			select_option(/** @type {HTMLSelectElement} */ (element), next.value);
 		}
 
 		for (let symbol of Object.getOwnPropertySymbols(effects)) {
@@ -514,10 +514,9 @@ export function attribute_effect(
 
 	if (is_select) {
 		var select = /** @type {HTMLSelectElement} */ (element);
-		var mounting = true;
+
 		effect(() => {
-			select_option(select, /** @type {Record<string | symbol, any>} */ (prev).value, mounting);
+			select_option(select, /** @type {Record<string | symbol, any>} */ (prev).value, true);
-			mounting = false;
 			init_select(select);
 		});
 	}

packages/svelte/src/internal/client/dom/elements/bindings/select.js

@@ -9,9 +9,9 @@ import * as w from '../../../warnings.js';
  * @template V
  * @param {HTMLSelectElement} select
  * @param {V} value
- * @param {boolean} [mounting]
+ * @param {boolean} mounting
  */
-export function select_option(select, value, mounting) {
+export function select_option(select, value, mounting = false) {
 	if (select.multiple) {
 		// If value is null or undefined, keep the selection as is
 		if (value == undefined) {