Fix for new b-tagging collections in EXOT27

Dan Guestrequested to merge
dguest/athena:fix-exot27 into 21.2

Some recent merge requests (specifically !25261 (merged)) broke a lot of derivations. This should fix EXOT27.

Attention @cpollard and @jburr. Also relates to ATLASDPD-1334.

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