fix(ci): bandaid for flaky macOS tests (#22239)

* fix(ci): bandaid for flaky macOS tests

* slightly increase timeout

Author: pront

.github/workflows/unit_mac.yml

@@ -47,7 +47,15 @@ jobs:
       - run: bash scripts/environment/bootstrap-macos.sh
       - run: bash scripts/environment/prepare.sh
       - run: echo "::add-matcher::.github/matchers/rust.json"
-      - run: make test
+
+      # Some tests e.g. `reader_exits_cleanly_when_writer_done_and_in_flight_acks` are flaky.
+      - name: Run tests
+        uses: nick-fields/retry@v3
+        with:
+          timeout_minutes: 45
+          max_attempts: 3
+          command: make test
+
       - run: make test-behavior
 
       - name: (PR review) Set latest commit status as ${{ job.status }}