Add install libraries step in test/macos

Author: davidalo

.github/workflows/test.yaml

@@ -83,6 +83,8 @@ jobs:
     steps:
       - name: checkout
         uses: actions/checkout@v4
+      - name: install libraries
+        run: brew install zstd
       - name: build and run tests
         run: cd test && make
       - name: run fuzz test target