[shawn] fix: type webview allowpopups as boolean for @types/react

@types/react's WebViewHTMLAttributes types allowpopups as
boolean | undefined, which shadows the project's electron.d.ts
declaration of string. Passing {true} renders identically to
"true" at runtime for the webview element, and clears the tsc error.

frontend/src/app/pages/Dashboard/BrowserCard.tsx

@@ -1054,7 +1054,7 @@ const BrowserCard: React.FC<Props> = ({
               }}
               data-tab-id={tab.id}
               src="about:blank"
-              allowpopups="true"
+              allowpopups={true}
               useragent={chromeUserAgent}
               {...(webviewPreloadPath ? { preload: webviewPreloadPath } : {})}
               webpreferences="plugins=yes, autoplayPolicy=no-user-gesture-required"