featureflag: Remove `AtomicFetchRemote`
The AtomicFetchRemote feature flag enables atomic fetches for a
repository. Since the feature flag is default enabled, remove the flag.
Related: #5640 (closed), #5670 (closed)
Edited by Justin Tobler
The AtomicFetchRemote feature flag enables atomic fetches for a
repository. Since the feature flag is default enabled, remove the flag.
Related: #5640 (closed), #5670 (closed)