runtime: Bump wasmtime from 38.0.4 to 44.0.1 (#6577)

* build(deps): bump wasmtime from 38.0.4 to 44.0.1

* runtime: Adapt to wasmtime 44 API changes

In wasmtime 42 `wasmtime::Error` was split from `anyhow::Error` and
`Config::async_support` became a no-op. Convert at the wasmtime
boundary so the rest of the runtime keeps using anyhow internally.

* server/http: Remove redundant .into_iter() (clippy)