Web vitals capture fixed on browsers predating Array.at()

1.396.3

Patch Changes

• #4020 e0ad8ef Thanks @posthog! - Fix TypeError: ....at is not a function thrown by the bundled web-vitals dependency on browsers that predate Array.prototype.at() (Chrome <92, iOS Safari <15.4). The web-vitals entrypoints now install a tiny Array.prototype.at polyfill before web-vitals runs, so web vitals capture works again on older browsers instead of crashing with an unhandled error. (2026-06-30)