Install missing nextest dependency for feature powerset

.github/workflows/feature_powerset.yml

@@ -50,6 +50,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: Swatinem/rust-cache@v2
       - uses: taiki-e/install-action@cargo-hack
+      - uses: taiki-e/install-action@nextest
 
       - name: Test
         run: cargo hack nextest run --no-fail-fast --feature-powerset --skip default --group-features jwt-ietf,jwt --group-features jwt-openid,jwt --clean-per-run --log-group github-actions --exclude-no-default-features --exclude-all-features