chore: Relax MSRV

Author: tottoto

Cargo.toml

@@ -14,7 +14,7 @@ description = "A Protocol Buffers implementation for the Rust Language."
 keywords = ["protobuf", "serialization"]
 categories = ["encoding"]
 edition = "2021"
-rust-version = "1.70"
+rust-version = "1.60"
 
 [workspace]
 members = [

README.md

@@ -46,8 +46,10 @@ See the [snazzy repository][snazzy] for a simple start-to-finish example.
 
 ### MSRV
 
-`prost` follows the `tokio-rs` project's MSRV model and supports 1.70. For more
-information on the tokio msrv policy you can check it out [here][tokio msrv]
+`prost` follows the `tokio-rs` project's MSRV model and supports 1.70. Some
+crates' MSRV might be lower than this version, see each `rust-version` field of
+the manifest file. For more information on the tokio msrv policy you can check
+it out [here][tokio msrv]
 
 [tokio msrv]: https://github.com/tokio-rs/tokio/#supported-rust-versions
 

prost-derive/Cargo.toml

@@ -12,7 +12,7 @@ documentation = "https://docs.rs/prost-derive"
 readme = "README.md"
 description = "A Protocol Buffers implementation for the Rust Language."
 edition = "2021"
-rust-version = "1.70"
+rust-version = "1.60"
 
 [lib]
 proc_macro = true

prost-types/Cargo.toml

@@ -12,7 +12,7 @@ documentation = "https://docs.rs/prost-types"
 readme = "README.md"
 description = "A Protocol Buffers implementation for the Rust Language."
 edition = "2021"
-rust-version = "1.70"
+rust-version = "1.60"
 
 [lib]
 doctest = false