ci: modernize ci with cargo fetch --locked

Author: Firestar99

.github/workflows/rust-ci.yml

@@ -22,34 +22,37 @@ jobs:
         with:
           components: clippy, rustfmt
 
+      - name: cargo fetch --locked
+        run: cargo fetch --locked
+
       # make sure all code has been formatted with rustfmt
       - name: check rustfmt
         run: cargo fmt -- --check --color always
 
       # run clippy to verify we have no warnings
-      - run: cargo fetch
       - name: cargo clippy
         run: cargo clippy --all-targets --all-features --  -D warnings
 
   test:
     name: Test
     strategy:
       matrix:
-        include:
-          - os: ubuntu-24.04
-            target: x86_64-unknown-linux-gnu
-          - os: windows-2025
-            target: x86_64-pc-windows-msvc
-          - os: macOS-15
-            target: aarch64-apple-darwin
+        os: [ ubuntu-24.04, windows-2022, macOS-latest ]
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v4
         with:
           submodules: true
-      - uses: dtolnay/rust-toolchain@stable
-      - run: cargo run -p install -- ${{matrix.target}} __internal__binaries__ "${{github.workspace}}/bin"
-      - run: cargo fetch
+      # just need a random command that forces the installation of rust-toolchain
+      # figure out native target triple while we're at it
+      - name: install rust-toolchain
+        run: echo "TARGET=$(rustc --print host-tuple)" >> "$GITHUB_ENV"
+      # Fetch dependencies in a separate step to clearly show how long each part
+      # of the testing takes
+      - name: cargo fetch --locked
+        run: cargo fetch --locked --target $TARGET
+      - run: cargo fetch --locked
+      - run: cargo run -p install -- $TARGET __internal__binaries__ "${{github.workspace}}/bin"
       - name: cargo test build
         run: cargo build --tests --release --all-features
       - name: cargo test
@@ -73,7 +76,6 @@ jobs:
       - uses: actions/checkout@v4
         with:
           submodules: true
-      - uses: dtolnay/rust-toolchain@stable
       - run: cargo fetch
       - name: cargo publish check
         run: cargo publish --dry-run --manifest-path spirv-tools-sys/Cargo.toml