Relax time limit for PushMeterRegistryTest.closeRespectsInterrupt() (#7044)

Signed-off-by: Johnny Lim <[email protected]>

Author: izeye

micrometer-core/src/test/java/io/micrometer/core/instrument/push/PushMeterRegistryTest.java

@@ -243,7 +243,7 @@ void closeRespectsInterrupt() throws InterruptedException {
         Thread closeThread = new Thread(registry::close, "simulatedShutdownHookThread");
         closeThread.start();
         // close is blocked (waiting for publish to finish)
-        await().atMost(Duration.ofMillis(100))
+        await().atMost(Duration.ofMillis(500))
             .pollInterval(1, MILLISECONDS)
             .untilAsserted(() -> assertThat(closeThread.getState()).isEqualTo(Thread.State.WAITING));