Update zipkin-reporter, ... to 2.15.4 (#247)

Co-authored-by: Simon Schenk <[email protected]>

project/Dependencies.scala

@@ -8,7 +8,7 @@ object Dependencies {
     val opentracing    = "0.33.0"
     val opentelemetry  = "0.7.1"
     val opencensus     = "0.26.0"
-    val zipkin         = "2.15.2"
+    val zipkin         = "2.15.4"
     val zio            = "1.0.3"
     val zioInteropCats = "2.1.4.0"
   }