fixup ci: unsafe usage on nightly and bump ed25519's MSRV

Author: baloo

.github/workflows/ed25519-dalek.yml

@@ -20,7 +20,7 @@ env:
 jobs:
 
   msrv:
-    name: Current MSRV is 1.60.0
+    name: Current MSRV is 1.81.0
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v3
@@ -29,5 +29,5 @@ jobs:
     - run: cargo update -Z minimal-versions
       # Now check that `cargo build` works with respect to the oldest possible
       # deps and the stated MSRV
-    - uses: dtolnay/rust-toolchain@1.60.0
+    - uses: dtolnay/rust-toolchain@1.81.0
     - run: cargo build

.github/workflows/workspace.yml

@@ -85,7 +85,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v3
-    - uses: dtolnay/rust-toolchain@1.73.0
+    - uses: dtolnay/rust-toolchain@1.81.0
       with:
         components: clippy
     - run: cargo clippy --target x86_64-unknown-linux-gnu --all-features

ed25519-dalek/Cargo.toml

@@ -16,7 +16,7 @@ keywords = ["cryptography", "ed25519", "curve25519", "signature", "ECC"]
 categories = ["cryptography", "no-std"]
 description = "Fast and efficient ed25519 EdDSA key generations, signing, and verification in pure Rust."
 exclude = [ ".gitignore", "TESTVECTORS", "VALIDATIONVECTORS", "res/*" ]
-rust-version = "1.60"
+rust-version = "1.81"
 
 [package.metadata.docs.rs]
 rustdoc-args = [