Exit-codes are not used by server

[anbraten]

The state send to the server contains an exit-code for the workflow. However as workflows have no exit-code they get simply ignored and are only considered by logging:

woodpecker/agent/runner.go

Lines 159 to 175 in 2bda190

	if canceled.IsSet() {
	state.Error = ""
	state.ExitCode = pipeline.ExitCodeKilled
	} else if err != nil {
	pExitError := &pipeline.ExitError{}
	switch {
	case errors.As(err, &pExitError):
	state.ExitCode = pExitError.Code
	case errors.Is(err, pipeline.ErrCancel):
	state.Error = ""
	state.ExitCode = pipeline.ExitCodeKilled
	canceled.SetTo(true)
	default:
	state.ExitCode = 1
	state.Error = err.Error()
	}
	}

In case of a canceled pipeline we even seem to remove the error:

woodpecker/agent/runner.go

Line 168 in 2bda190

state.Error = ""

sounds to be related to #2197