cargo: bump MSRV to 1.81 (#539)

Signed-off-by: Luca BRUNO <[email protected]>

Author: lucab

.github/workflows/rust.yml

@@ -9,9 +9,9 @@ on:
 env:
   CARGO_TERM_COLOR: always
   # Pinned toolchain for linting and benchmarks
-  ACTIONS_LINTS_TOOLCHAIN: 1.78.0
+  ACTIONS_LINTS_TOOLCHAIN: 1.81.0
   # Minimum supported Rust version (MSRV)
-  ACTION_MSRV_TOOLCHAIN: 1.74.0
+  ACTION_MSRV_TOOLCHAIN: 1.81.0
   EXTRA_FEATURES: "protobuf push process"
 
 jobs:

Cargo.toml

@@ -9,6 +9,7 @@ license = "Apache-2.0"
 name = "prometheus"
 readme = "README.md"
 repository = "https://github.com/tikv/rust-prometheus"
+rust-version = "1.81"
 version = "0.13.4"
 
 [package.metadata.docs.rs]