`std` has had `pin!` macro for some time, there is no need for us to use the older alternatives. Cannot disallow `tokio::pin` because tokio macros use that.
## Problem `block_in_place` is a quite expensive operation, and if it is used, we should explicitly have to opt into it by allowing the `clippy::disallowed_methods` lint. For more, see https://github.com/neondatabase/neon/pull/5023#discussion_r1304194495. Similar arguments exist for `Handle::block_on`, but we don't do this yet as there is still usages. ## Summary of changes Adds a clippy.toml file, configuring the [`disallowed_methods` lint](https://rust-lang.github.io/rust-clippy/master/#/disallowed_method).
