Fix flaky QUIC hole-punching tests (#314)

.github/workflows/hole-punch-interop.yml

@@ -11,9 +11,19 @@ on:
 
 name: libp2p holepunching interop test
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   run-hole-punch-interop:
     runs-on: ['self-hosted', 'linux', 'x64', '4xlarge'] # https://github.com/pl-strflt/tf-aws-gh-runner/blob/main/runners.tf
+# Uncomment to test for flakiness.
+#    strategy:
+#      matrix:
+#        dim1: ['a', 'b', 'c', 'd', 'e']
+#        dim2: [1, 2, 3, 4, 5]
+#      fail-fast: false
     steps:
       - uses: actions/checkout@v3
       - uses: ./.github/actions/run-interop-hole-punch-test