bump rust toolchain to 1.81

Signed-off-by: June Clementine Strawberry <june@3.dog>

.github/workflows/ci.yml

@@ -92,14 +92,14 @@ jobs:
       - name: Install MSRV toolchain
         uses: dtolnay/rust-toolchain@master
         with:
-          toolchain: "1.75"
+          toolchain: "1.81"
 
       - uses: Swatinem/rust-cache@v2
         with:
           # A stable compiler update should automatically not reuse old caches.
           # Add the MSRV as a stable cache key too so bumping it also gets us a
           # fresh cache.
-          shared-key: msrv1.75
+          shared-key: msrv1.81
 
       - name: Get xtask
         uses: actions/cache@v4

Cargo.toml

@@ -5,7 +5,7 @@ default-members = ["crates/*"]
 resolver = "2"
 
 [workspace.package]
-rust-version = "1.75"
+rust-version = "1.81"
 
 [workspace.dependencies]
 as_variant = "1.2.0"

xtask/src/ci.rs

@@ -16,7 +16,7 @@ use reexport_features::check_reexport_features;
 use spec_links::check_spec_links;
 use unused_features::check_unused_features;
 
-const MSRV: &str = "1.75";
+const MSRV: &str = "1.81";
 
 #[derive(Args)]
 pub struct CiArgs {