Merge branch 'ps/upload-pack-oom-protection' into maint-2.51

A broken or malicious "git fetch" can say that it has the same object for many many times, and the upload-pack serving it can exhaust memory storing them redundantly, which has been corrected. * ps/upload-pack-oom-protection: upload-pack: don't ACK non-commits repeatedly in protocol v2 t5530: modernize tests