ref(core): Avoid boxing in DateUtils.nanosToDate (#5523)

* ref(core): Avoid boxing in DateUtils.nanosToDate

nanosToMillis already returns a primitive double, but the result was
stored in a boxed Double and then unboxed again via longValue(). Keep
the value primitive to drop the redundant allocation and unboxing on
this conversion, which runs whenever a SentryDate is turned into a
java.util.Date.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* changelog

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: runningcode

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## Unreleased
+
+### Improvements
+
+- Reduce unboxing in `DateUtils.nanosToDate` ([#5523](https://github.com/getsentry/sentry-java/pull/5523))
+
 ## 8.43.2
 
 ### Improvements

sentry/src/main/java/io/sentry/DateUtils.java

@@ -115,8 +115,8 @@ public static double nanosToMillis(final double nanos) {
    * @return date rounded down to milliseconds
    */
   public static Date nanosToDate(final long nanos) {
-    final Double millis = nanosToMillis((double) nanos);
-    return getDateTime(millis.longValue());
+    final double millis = nanosToMillis((double) nanos);
+    return getDateTime((long) millis);
   }
 
   public static @Nullable Date toUtilDate(final @Nullable SentryDate sentryDate) {