chore: Bump MSRV to 1.70 (#982)

Rust 1.70 is 7 month old at this time. A transient dependency `home` requires at least rust 1.70.

prost-build v0.12.3 (/workspaces/prost/prost-build)
└── which v4.4.2
    └── home v0.5.9

.github/workflows/ci.yml

@@ -33,7 +33,7 @@ jobs:
       matrix:
         toolchain:
           - stable
-          - "1.65"
+          - "1.70"
         os:
           - ubuntu-latest
           - macos-latest

Cargo.toml

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

README.md

@@ -44,7 +44,7 @@ start-to-finish example.
 
 ### MSRV
 
-`prost` follows the `tokio-rs` project's MSRV model and supports 1.60. For more
+`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]
 
 [tokio msrv]: https://github.com/tokio-rs/tokio/#supported-rust-versions

prost-build/Cargo.toml

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

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 = "1.60"
+rust-version = "1.70"
 
 [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 = "1.60"
+rust-version = "1.70"
 
 [lib]
 doctest = false