chore: add wfe-server crates to workspace, update test contexts

Add wfe-server-protos and wfe-server to workspace members.
Update StepExecutionContext constructions with log_sink: None
in buildkit and containerd test files.

wfe-containerd/tests/integration.rs

@@ -75,6 +75,7 @@ fn make_context<'a>(
         workflow,
         cancellation_token: tokio_util::sync::CancellationToken::new(),
         host_context: None,
+                log_sink: None,
     }
 }