Backport patches for more git-fetch(1) optimizations
Backport 60aae8731c (Merge branch 'ps/fetch-mirror-optim' into next, 2022-03-08), upstreamed as part of git#104 (closed).
Backport 60aae8731c (Merge branch 'ps/fetch-mirror-optim' into next, 2022-03-08), upstreamed as part of git#104 (closed).