Run kani as part of the CI pipeline

Run kani as a part of the CI pipeline. In particular, run the proofs for
virtio-queue. In some cases, kani may not finish so set a twenty minutes
timeout.

Signed-off-by: Matias Ezequiel Vara Larsen <[email protected]>

Author: MatiasVara

.buildkite/custom-tests.json

@@ -48,6 +48,12 @@
       "command": "cd fuzz && cargo test --package common --lib blk && cargo +nightly fuzz run blk -- -max_total_time=900 -timeout=60s",
       "platform": ["x86_64", "aarch64"],
       "timeout_in_minutes": 20
+    },
+    {
+      "test_name": "prove-virtio-queue",
+      "command": "cargo kani --package virtio-queue",
+      "platform": ["x86_64", "aarch64"],
+      "timeout_in_minutes": 20
     }
   ]
 }