Bump rapids-4-spark_2.12 in /jvm-packages/xgboost4j-spark-gpu

Bumps rapids-4-spark_2.12 from 23.04.1 to 23.06.0.

---
updated-dependencies:
- dependency-name: com.nvidia:rapids-4-spark_2.12
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

jvm-packages/pom.xml

@@ -44,7 +44,7 @@
         <log.capi.invocation>OFF</log.capi.invocation>
         <use.cuda>OFF</use.cuda>
         <cudf.version>23.04.0</cudf.version>
-        <spark.rapids.version>23.04.1</spark.rapids.version>
+        <spark.rapids.version>23.06.0</spark.rapids.version>
         <cudf.classifier>cuda11</cudf.classifier>
         <scalatest.version>3.2.16</scalatest.version>
         <scala-collection-compat.version>2.10.0</scala-collection-compat.version>