chore: bump MSRV to 1.57

Motivation: to improve panic messages in const fns, which without this are a
horrible experience for users. As we make more `from_static` constructors
usable in a const context, this is worth the increase.

We're still able to build on Debian oldstable.

Author: seanmonstar

Cargo.toml

@@ -19,9 +19,8 @@ A set of types for representing HTTP requests and responses.
 """
 keywords = ["http"]
 categories = ["web-programming"]
-edition = "2018"
-# When updating this value, don't forget to also adjust the GitHub Actions config.
-rust-version = "1.49.0"
+edition = "2021"
+rust-version = "1.57.0"
 
 [workspace]
 members = [

README.md

@@ -62,9 +62,9 @@ fn main() {
 
 # Supported Rust Versions
 
-This project follows the [Tokio MSRV][msrv] and is currently set to `1.49`.
+This project follows the [hyper's MSRV _policy_][msrv], though it can be lower, and is currently set to `1.57`.
 
-[msrv]: https://github.com/tokio-rs/tokio/#supported-rust-versions
+[msrv]: https://hyper.rs/contrib/msrv/
 
 # License