servo crashes when trying to load www.startpage.com

[feature-engineer]

Describe the bug: When trying to load www.startpage.com, servo shows a message saying it had crashed. It complains that iframe should have browsing context. The logger had this to say:

iframe should have browsing context (thread Script(1,7), at components/script/dom/globalscope.rs:2427) [2024-06-03T10:26:02Z ERROR servoshell] iframe should have browsing context

To Reproduce: Browse to www.startpage.com

Platform: Specify OS, distribution, and hardware platform. Manjaro Linux XFCE, nvidia gtx 1080.