Cargo: Add rust-version field

see https://doc.rust-lang.org/cargo/reference/manifest.html#the-rust-version-field

Author: Turbo87

.github/workflows/ci.yml

@@ -19,6 +19,8 @@ jobs:
           - stable
           - beta
           - nightly
+          # When updating this value, don't forget to also adjust the
+          # `rust-version` field in the `Cargo.toml` file.
           - 1.46.0
 
         include:

Cargo.toml

@@ -20,6 +20,8 @@ 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 = "1.46.0"
 
 [dependencies]
 bytes = "1"