ref(core): Remove unnecessary boxing (JAVA-554)

Replace Integer.valueOf/Double.valueOf boxing with primitives or the
appropriate parse method. String.format takes the primitives directly,
the double conversions only need a cast, and the version check parses
straight to a primitive double via Double.parseDouble.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: runningcode

sentry/src/main/java/io/sentry/CircularFifoQueue.java

@@ -258,8 +258,7 @@ public boolean add(final @NotNull E element) {
     if (index < 0 || index >= sz) {
       throw new NoSuchElementException(
           String.format(
-              "The specified index (%1$d) is outside the available range [0, %2$d)",
-              Integer.valueOf(index), Integer.valueOf(sz)));
+              "The specified index (%1$d) is outside the available range [0, %2$d)", index, sz));
     }
 
     final int idx = (start + index) % maxElements;

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

@@ -115,7 +115,7 @@ 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.valueOf(nanos));
+    final Double millis = nanosToMillis((double) nanos);
     return getDateTime(millis.longValue());
   }
 
@@ -137,7 +137,7 @@ public static Date nanosToDate(final long nanos) {
    * @return seconds
    */
   public static double nanosToSeconds(final long nanos) {
-    return Double.valueOf(nanos) / (1000.0 * 1000.0 * 1000.0);
+    return (double) nanos / (1000.0 * 1000.0 * 1000.0);
   }
 
   /**

sentry/src/main/java/io/sentry/util/Platform.java

@@ -23,7 +23,7 @@ public final class Platform {
     try {
       final @Nullable String javaStringVersion = System.getProperty("java.specification.version");
       if (javaStringVersion != null) {
-        final @NotNull double javaVersion = Double.valueOf(javaStringVersion);
+        final @NotNull double javaVersion = Double.parseDouble(javaStringVersion);
         isJavaNinePlus = javaVersion >= 9.0;
       } else {
         isJavaNinePlus = false;