use hack for clippy

Author: molpopgen

.github/workflows/tests.yml

@@ -78,6 +78,7 @@ jobs:
           toolchain: ${{ matrix.rust }}
           override: true
       - uses: Swatinem/rust-cache@v1
+      - uses: taiki-e/install-action@cargo-hack
       - run: rustup component add clippy
       - name: clippy (all targets, feature powerset)
         run: cargo hack clippy --all-targets --feature-powerset -- -D warnings