SetChatTokeUsage should only run when then response is not streamed in OpenAiBasedProviderClientBase

Tested this is 2 scenarios and both are fixed by this MR. Thank you @marcus_johansson

Thank you, getting merged.

Now that this issue is closed, please review the contribution record.

As a contributor, attribute any organization helped you, or if you volunteered your own time.

Maintainers, please credit people who helped resolve this issue.