hotfix: Update Phoenix to patch CVE 2026-32689

[joshlarson]

Scope

No Asana ticket.
Slack thread
CVE 2026-32689

Notes

There is what looks like an extraneous change in schedule_view.ex. Without this change, we were seeing 👇 error:

== Compilation error in file lib/dotcom_web/views/schedule_view.ex ==
** (RuntimeError) duplicate call to "use Phoenix.VerifiedRoutes" found, make sure it is used only once per module
    (phoenix 1.8.6) lib/phoenix/verified_routes.ex:269: Phoenix.VerifiedRoutes.__using__/2
    lib/dotcom_web/views/schedule_view.ex:5: (module)

Since schedule_view.ex is use-ing both :component and :view from DotcomWeb, it doesn't need to re-import the view_helpers() from the definition of :component, so replacing use DotcomWeb, :component with use Phoenix.Component should change nothing.