Context is no longer Send/Sync

[CaptainMaso]

I have some code using Gotham that requires async handlers to be Send + Sync.

I am using Tera to template the data returned from asynchronously from a database into HTML, which I think is a fairly common use-case.

As tera::Context is no longer Send/Sync, using it across await boundaries within the asynchronous function handlers causes the whole future to be not Send/Sync, meaning it cannot be used in many asynchronous web servers (I have checked Gotham, Rocket and Axum all require their handlers to be Send at the very least).

I'm sure the behaviour can be worked around, but as this was not an issue with Tera in previous versions, updating to 1.13 would break many peoples code.

I have seen #681, but as this is an issue with the code, thought it would be worth mentioning for anyone searching for results about this problem.

[Keats]

This was unintended and will be changed back for the next release