[central-frontend] CSP blocking sentry reports

[alxndrsn]

It looks like Sentry reports for web-forms &/or other frontend apps are blocked by the CSP: https://getodk.sentry.io/issues/7600919924/

TODO

• fully confirm
  • which frontend app(s) are affected
  • if these connections are legit

Suggested fixes

Either:

1. allow connect-src for .sentry.io, or the full DSN, or
2. proxy sentry requests through nginx (Consider adding a proxy for frontend Sentry events #2006)

[lognaturel]

We have received several reports: https://getodk.sentry.io/projects/webforms-cloud/?project=4511508552220672 so it must not be blocking everything.

[matthew-white]

Closed by #2066.