Support engines that don't accept secrets and resources or explicitly error

[iwahbe]

Hello!

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Issue details

The RPC framework sends a Configure request where the engine can declare that it doesn't support receiving secrets or resources. To comply with the gRPC protocol, we should either:

• Store these values and appropriately not send resource values and secret values to the engine, or
• Error on old engines when these flags are not set

Affected area/feature

pulumi-go-provider/provider.go

Lines 722 to 741 in 63fe29d

	func (p *provider) Configure(ctx context.Context, req *rpc.ConfigureRequest) (*rpc.ConfigureResponse, error) {
	ctx = p.ctx(ctx, "")
	argMap, err := p.getMap(req.GetArgs())
	if err != nil {
	return nil, err
	}
	err = p.client.Configure(ctx, ConfigureRequest{
	Variables: req.GetVariables(),
	Args: argMap,
	})
	if err != nil {
	return nil, err
	}
	return &rpc.ConfigureResponse{
	AcceptSecrets: true,
	SupportsPreview: true,
	AcceptResources: true,
	AcceptOutputs: true,
	}, nil
	}

[EronWright]

There's some precedent for throwing an error, as we do when AcceptsOutputValues is false.