@Tanul As per the error message it couldn't load Microsoft.Azure.WebJobs.Host.Scale.ConcurrenyManager so looks like you have enabled the concurrency for your function app. Can you install the latest release of the function app tool as I see the old version of the function runtime version and confirm if it helps.
In case if you still observe the issue then I will suggest you to post your query in azure functions core tools github issue so the experts can assist you further.