use !! to coerce navigator.userAgent to a boolean

Co-authored-by: dconeybe <[email protected]>

Author: Yonom

packages/util/src/environment.ts

@@ -138,7 +138,7 @@ export function isNodeSdk(): boolean {
 export function isSafari(): boolean {
   return (
     !isNode() &&
-    navigator.userAgent &&
+    !!navigator.userAgent &&
     navigator.userAgent.includes('Safari') &&
     !navigator.userAgent.includes('Chrome')
   );