ci: Use swatinem/rust-cache@v2 in all CI workflows. (#230)

.github/workflows/deploy-book.yml

@@ -2,8 +2,8 @@ name: Deploy book
 on:
   # Deploy the book when the Rust (Linux) workflow completes on main
   workflow_run:
-    workflows: ["Rust (Linux)"]
-    branches: [main]
+    workflows: [ "Rust (Linux)" ]
+    branches: [ main ]
     types:
       - completed
 
@@ -18,6 +18,7 @@ jobs:
       - uses: actions/checkout@v4
         with:
           fetch-depth: 0
+      - uses: swatinem/rust-cache@v2
       - name: Install latest mdbook
         run: |
           tag=$(curl 'https://api.github.com/repos/rust-lang/mdbook/releases/latest' | jq -r '.tag_name')

.github/workflows/linux.yml

@@ -19,6 +19,7 @@ jobs:
       - uses: actions/checkout@v4
         with:
           submodules: true
+      - uses: swatinem/rust-cache@v2
       - name: Run Clippy
         run: cargo clippy --all-targets --features highs,cbc --all --exclude ipm-simd
       - name: Install latest mdbook
@@ -44,6 +45,7 @@ jobs:
       - uses: actions/checkout@v4
         with:
           submodules: true
+      - uses: swatinem/rust-cache@v2
       - name: Build
         run: cargo build --verbose --no-default-features --package [email protected]
       - name: Run tests

.github/workflows/python.yml

@@ -65,6 +65,7 @@ jobs:
       - uses: actions/checkout@v4
         with:
           submodules: true
+      - uses: swatinem/rust-cache@v2
       - uses: actions/setup-python@v5
         with:
           python-version: ${{ matrix.python-version }}
@@ -98,6 +99,7 @@ jobs:
       - uses: actions/checkout@v4
         with:
           submodules: true
+      - uses: swatinem/rust-cache@v2
       - uses: actions/setup-python@v5
         with:
           python-version: ${{ matrix.python-version }}

.github/workflows/windows.yml

@@ -21,6 +21,7 @@ jobs:
       - uses: actions/checkout@v4
         with:
           submodules: true
+      - uses: swatinem/rust-cache@v2
       - name: Run Clippy
         run: cargo clippy --all-targets --features highs,cbc
       - name: Build