chore(deps): update @google-cloud/firestore to ^8.0.0#3105

ouzkilic wants to merge 2 commits intofirebase:mainfirebase/firebase-admin-node:mainfrom

ouzkilic:fix/update-google-cloud-firestore-optional-depouzkilic/firebase-admin-node:fix/update-google-cloud-firestore-optional-depCopy head branch name to clipboard