https://en.m.wikipedia.org/wiki/Distributed_ledger no need to talk automatically, only distribution necessary without single point of failure. say „synchronized“, if you mean realtime synchronized then not in git, but synchronized manually.

https://en.m.wikipedia.org/wiki/Consensus_(computer_science) only need to determine which block to commit to database, access key do that. if meant in term of „which repo is real one“, signed commit optional feature, maybe that speak against it being blockchain because not by default.

Ledger: repository database.

Consensus algorithm: repository access key.

https://git-scm.com/