consul:no return err even if ctx is done

[wuqinqiang]

What happened:

file:consul/watcher.go

no return err even if ctx is done.

file:consul/registry.go

• goroutine has no exit.
• get service has different timeout.

What you expected to happen:

How to reproduce it (as minimally and precisely as possible):

Anything else we need to know?:

Environment:

• Kratos version v2.5.3
• Go version go1.18.3