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[suhaibmujahid]

Fixes #1841

Checklist

• Type annotations added to new functions
• Docs added to functions touched in main classes
• Dry-run produced the expected results
• The to-be-announced tag added if this is worth announcing

[suhaibmujahid]

By matching core-security group I found only 84 duplicate bugs (gets filtered to 27 bugs).

@rvandermeulen suggested matching any group that has the "sec" substring, which catches 856 duplicate bugs (gets filtered to 304 bugs).

[dveditz]

In issue 1841 I meant to do a substring match when I said "contains core-security", I didn't mean an exact match (I'm sorry I wasn't very precise). The bugs will have miscellaneous groups like dom-core-security, javascript-core-security, core-security-release, etc. Only a subset will have literal "core-security".