chore: Bump MSRV to 1.70

Author: killzoner

Cargo.toml

@@ -6,7 +6,7 @@ resolver = "2"
 repository = "https://github.com/assert-rs/snapbox/"
 license = "MIT OR Apache-2.0"
 edition = "2021"
-rust-version = "1.65"  # MSRV
+rust-version = "1.70"  # MSRV
 include = [
   "build.rs",
   "src/**/*",