Modernize java.time API usages

See gh-35861
Signed-off-by: Vincent Potucek <vpotucek@me.com>

spring-context/src/main/java/org/springframework/format/datetime/standard/DateTimeConverters.java

@@ -81,8 +81,7 @@ final class DateTimeConverters {
 			return gc.toZonedDateTime();
 		}
 		else {
-			return ZonedDateTime.ofInstant(Instant.ofEpochMilli(source.getTimeInMillis()),
-					source.getTimeZone().toZoneId());
+			return Instant.ofEpochMilli(source.getTimeInMillis()).atZone(source.getTimeZone().toZoneId());
 		}
 	}
 

spring-context/src/main/java/org/springframework/scheduling/support/CronTrigger.java

@@ -115,7 +115,7 @@ public class CronTrigger implements Trigger {
 	public @Nullable Instant nextExecution(TriggerContext triggerContext) {
 		Instant timestamp = determineLatestTimestamp(triggerContext);
 		ZoneId zone = (this.zoneId != null ? this.zoneId : triggerContext.getClock().getZone());
-		ZonedDateTime zonedTimestamp = ZonedDateTime.ofInstant(timestamp, zone);
+		ZonedDateTime zonedTimestamp = timestamp.atZone(zone);
 		ZonedDateTime nextTimestamp = this.expression.next(zonedTimestamp);
 		return (nextTimestamp != null ? nextTimestamp.toInstant() : null);
 	}

spring-context/src/test/java/org/springframework/scheduling/concurrent/DefaultManagedTaskSchedulerTests.java

@@ -18,7 +18,6 @@ package org.springframework.scheduling.concurrent;
 
 import java.time.Duration;
 import java.time.Instant;
-import java.time.temporal.ChronoUnit;
 
 import org.assertj.core.api.ThrowableAssert.ThrowingCallable;
 import org.junit.jupiter.api.Test;
@@ -53,28 +52,28 @@ class DefaultManagedTaskSchedulerTests {
 	void scheduleAtFixedRateWithStartTimeAndDurationAndNoScheduledExecutorProvidesDedicatedException() {
 		DefaultManagedTaskScheduler scheduler = new DefaultManagedTaskScheduler();
 		assertNoExecutorException(() -> scheduler.scheduleAtFixedRate(
-				NO_OP, Instant.now(), Duration.of(1, ChronoUnit.MINUTES)));
+				NO_OP, Instant.now(), Duration.ofMinutes(1)));
 	}
 
 	@Test
 	void scheduleAtFixedRateWithDurationAndNoScheduledExecutorProvidesDedicatedException() {
 		DefaultManagedTaskScheduler scheduler = new DefaultManagedTaskScheduler();
 		assertNoExecutorException(() -> scheduler.scheduleAtFixedRate(
-				NO_OP, Duration.of(1, ChronoUnit.MINUTES)));
+				NO_OP, Duration.ofMinutes(1)));
 	}
 
 	@Test
 	void scheduleWithFixedDelayWithStartTimeAndDurationAndNoScheduledExecutorProvidesDedicatedException() {
 		DefaultManagedTaskScheduler scheduler = new DefaultManagedTaskScheduler();
 		assertNoExecutorException(() -> scheduler.scheduleWithFixedDelay(
-				NO_OP, Instant.now(), Duration.of(1, ChronoUnit.MINUTES)));
+				NO_OP, Instant.now(), Duration.ofMinutes(1)));
 	}
 
 	@Test
 	void scheduleWithFixedDelayWithDurationAndNoScheduledExecutorProvidesDedicatedException() {
 		DefaultManagedTaskScheduler scheduler = new DefaultManagedTaskScheduler();
 		assertNoExecutorException(() -> scheduler.scheduleWithFixedDelay(
-				NO_OP, Duration.of(1, ChronoUnit.MINUTES)));
+				NO_OP, Duration.ofMinutes(1)));
 	}
 
 	private void assertNoExecutorException(ThrowingCallable callable) {