Replace Thread.sleep and Testing.whileTimeout with Awaitility in tests

[jnioche]

Summary

• Replace hand-rolled Thread.sleep polling loops and Testing.whileTimeout calls with Awaitility across 6 test files
• Async waits now exit as soon as the condition is met instead of sleeping for a fixed duration, improving both test speed and reliability on slow CI machines

Files changed

File	Before	After
RocksDbStoreTest	do { Thread.sleep(1) } while (...) loop with manual attempt counter	Awaitility.await().until(...)
DRPCTest	while (System.currentTimeMillis() < deadline) + Thread.sleep(1)	Awaitility.await().until(...)
AsyncLocalizerTest	while (...) Thread.sleep(1) waiting for file deletion	Awaitility.await().until(() -> !file.exists())
AuthTest	Testing.whileTimeout + Time.sleep(100)	Awaitility.await().until(server::isServing)
MetricsIntegrationTest	Testing.whileTimeout in waitForAtLeastNBuckets	Awaitility.with().until(...) (now consistent with assertMetricRunningSum which already used Awaitility)
NettyTest	4 patterns: manual polling loop, sleep() helper, 3x Testing.whileTimeout	Awaitility.await().until(...) throughout

Not changed

• ServerUtilsTest.sleepInterrupted() — intentionally tests thread interrupt behavior
• NettyTest.doTestServerDelayed Thread.sleep(100) — deliberate delay simulating a late server start, not polling
• LocalFsBlobStoreTest Thread.sleep(2) — waits for filesystem timestamp resolution, not a polling pattern

Test plan

• RocksDbStoreTest — 4 tests pass
• DRPCTest — 6 tests pass
• AsyncLocalizerTest — 17 tests pass
• AuthTest — 13 tests pass
• MetricsIntegrationTest — 2 tests pass
• NettyTest — 13 tests pass

🤖 Generated with Claude Code