Motivation is as follows:
- etcdctl we only depend on clientv3 APIs, no dependencies of bolt, backend, mvcc, file-layout
- etcdctl can be officially supported across wide range of versions, while etcdutl is pretty specific to file format at particular version.
it's step towards desired modules layout, documented in: https://etcd.io/docs/next/dev-internal/modules/
instead of v3.0.0-000101010000000-00000000000,
that might be misleading as we don't develop etcd v3.0.0 any longer.
This version is a virtual version and is not supposed to be tagged
within the repository. We should tag real versions like: 3.5.0-alpha.0.
Please notice that go.etcd.io/etcd/client/v2 will be versioned as `v2.305.0-pre`.
The reason is that client v2 must have v2 version. I propose a
convention to envode the major version as 100x in minor version to make
the association to the underlying repository clear, staying within v2
version family.
The change was generated using:
```
DRY_RUN=false TARGET_VERSION="v3.5.0-pre" ./scripts/release_mod.sh update_versions
```
