regression tracking uses incorrect reference version for bullseye-security

According to https://debusine.debian.net/debian/developers/work-request/572100/#qa , regression tracking is performed against +deb11u3 (bullseye) instead of +deb11u4 (bullseye-security, the version currently in use).

I believe it should use the latest published version for more pertinent QA results.

#572100: upload-to-bullseye-security: perl_5.32.1-4+deb11u5
Original result for 5.32.1-4+deb11u3
     New result for 5.32.1-4+deb11u5