Update icu4j to 78.1

Author: typelevel-steward[bot]

build.sbt

@@ -12,7 +12,7 @@ def DefaultScalaVersion: String = Scala213
 val catsCollectionsV = "0.9.10"
 val catsV            = "2.13.0"
 val disciplineMunitV = "2.0.0"
-val icu4jV           = "73.2"
+val icu4jV           = "78.1"
 val literallyV       = "1.2.0"
 val munitV           = "1.1.1"
 val munitScalacheckV = "1.1.0"