Consistent reservoir sampling span processor (#352)

* upgraded to hipparchus 2.1

* consistent reservoir sampling span processor

* made constant package private

Author: oertl

consistent-sampling/build.gradle.kts

@@ -7,6 +7,6 @@ description = "Sampler and exporter implementations for consistent sampling"
 
 dependencies {
   api("io.opentelemetry:opentelemetry-sdk-trace")
-  testImplementation("org.hipparchus:hipparchus-core:2.0")
-  testImplementation("org.hipparchus:hipparchus-stat:2.0")
+  testImplementation("org.hipparchus:hipparchus-core:2.1")
+  testImplementation("org.hipparchus:hipparchus-stat:2.1")
 }