Expiry email resent for previously expiring metrics even if that bug was already closed

[badboy]

e.g. we sent emails for browser.searchinit.engine_invalid_webextension with https://bugzilla.mozilla.org/show_bug.cgi?id=1994584 on 2025-10-16 and 2025-10-23

The bug was tackled and closed on 2025-10-18. We still resent the email later.
I think we're missing a check for a bug's status.
We gather a list of bugs here:

probe-scraper/probe_scraper/fog_checks.py

Line 284 in 07baa08

for bug_url, bug_metrics in filed_bugs.items():

But we never check if that bug is already closed. If it is we should remove it from the list.