update the roadmap: etcd 3.6.0 will depend on bbolt 1.4.0 instead of …

…1.3.8

Signed-off-by: Benjamin Wang <wachao@vmware.com>

Documentation/contributor-guide/roadmap.md

@@ -20,7 +20,7 @@ For a full list of tasks in v3.6.0, please see [milestone etcd-v3.6](https://git
 | [Support downgrade](https://github.com/etcd-io/etcd/issues/11716)                                                  | P0       | etcd will support downgrade starting from 3.6.0. But it will also support offline downgrade from 3.5 to 3.4. |
 | [StoreV2 deprecation](https://github.com/etcd-io/etcd/issues/12913)                                                | P0       | This task will be covered in both 3.6 and 3.7.                                                               |
 | [Release raft 3.6.0](https://github.com/etcd-io/raft/issues/89)                                                    | P0       | etcd 3.6.0 will depends on raft 3.6.0                                                                        |
-| [Release bbolt 1.3.8](https://github.com/etcd-io/bbolt/issues/542)                                                 | P0       | etcd 3.6.0 will depends on bbolt 1.3.8                                                                       |
+| [Release bbolt 1.4.0](https://github.com/etcd-io/bbolt/issues/553)                                                 | P0       | etcd 3.6.0 will depends on bbolt 1.4.0                                                                       |
 | [Support /livez and /readyz endpoints](https://github.com/etcd-io/etcd/issues/16007)                               | P1       | It provides clearer APIs, and can also workaround the stalled writes issue                                   |
 | [Bump gRPC](https://github.com/etcd-io/etcd/issues/16290)                                                          | P1       | It isn't guaranteed to be resolved in 3.6, and might be postponed to 3.7 depending on the effort and risk.   |
 | [Deprecate grpc-gateway or bump it](https://github.com/etcd-io/etcd/issues/14499)                                  | P1       | It isn't guaranteed to be resolved in 3.6, and might be postponed to 3.7 depending on the effort and risk.   |