ci: add workflow permissions (#6)

Author: DanielleHuisman

.github/workflows/ci.yml

@@ -6,6 +6,9 @@ on:
         branches:
             - main
 
+permissions:
+    contents: read
+
 env:
     RUSTFLAGS: '-Dwarnings'
 
@@ -19,13 +22,10 @@ jobs:
               uses: actions/checkout@v4
 
             - name: Set up Rust toolchain
-              run: rustup toolchain install stable --no-self-update --profile default --target wasm32-unknown-unknown
-
-            - name: Set up Rust cache
-              uses: swatinem/rust-cache@v2
+              uses: actions-rust-lang/setup-rust-toolchain@v1
               with:
-                  cache-on-failure: true
-                  save-if: ${{ github.ref == 'refs/heads/main' }}
+                  components: clippy, rustfmt
+                  target: wasm32-unknown-unknown
 
             - name: Check formatting
               run: cargo fmt --all --check