fix: try catch strict_equals to avoid error accessing STATE_SYMBOL (#13216)

Can error if trying to access something while in a secure context, like iframe, sandboxes, etc. Fixes #13214

Author: paoloricciuti

.changeset/late-geckos-draw.md

@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: try catch `strict_equals` to avoid error accessing `STATE_SYMBOL`

packages/svelte/src/internal/client/dev/equality.js

@@ -78,9 +78,13 @@ export function init_array_prototype_warnings() {
  * @returns {boolean}
  */
 export function strict_equals(a, b, equal = true) {
-	if ((a === b) !== (get_proxied_value(a) === get_proxied_value(b))) {
-		w.state_proxy_equality_mismatch(equal ? '===' : '!==');
-	}
+	// try-catch needed because this tries to read properties of `a` and `b`,
+	// which could be disallowed for example in a secure context
+	try {
+		if ((a === b) !== (get_proxied_value(a) === get_proxied_value(b))) {
+			w.state_proxy_equality_mismatch(equal ? '===' : '!==');
+		}
+	} catch {}
 
 	return (a === b) === equal;
 }