chore: unused features CI

.github/workflows/ci.yaml

@@ -18,26 +18,36 @@ jobs:
         - beta
         - nightly
     steps:
-    - uses: actions/checkout@v4
-    - name: Install Foundry
-      uses: foundry-rs/foundry-toolchain@v1
-    - run: rustup update ${{ matrix.toolchain }} && rustup default ${{ matrix.toolchain }}
-    - run: cargo test --workspace --all-features --all-targets
-    - run: cargo test --workspace --all-features --doc
+      - uses: actions/checkout@v4
+      - name: Install Foundry
+        uses: foundry-rs/foundry-toolchain@v1
+      - run: rustup update ${{ matrix.toolchain }} && rustup default ${{ matrix.toolchain }}
+      - run: cargo test --workspace --all-features --all-targets
+      - run: cargo test --workspace --all-features --doc
 
   clippy:
     name: Clippy
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
-    - run: cargo clippy --all-targets --all-features -- -D warnings
+      - uses: actions/checkout@v4
+      - run: cargo clippy --all-targets --all-features -- -D warnings
 
   fmt:
     name: Formatting
     runs-on: ubuntu-latest
     steps:
-        - uses: actions/checkout@v4
-        - run: cargo fmt --all -- --check
+      - uses: actions/checkout@v4
+      - run: cargo fmt --all -- --check
+
+  unused-features:
+    name: Unused features
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - run: cargo install cargo-unused-features
+      - run: unused-features analyze
+      - run: git diff
+      - run: if [ -n "$(git diff)" ]; then exit 1; fi
 
   # `git diff bytecode` shows changes but I'm not sure why. Disabling for now
   # verify-bytecode: