Update zio, zio-streams, zio-test, ... to 2.1.21

Author: zio-scala-steward[bot]

project/Dependencies.scala

@@ -4,7 +4,7 @@ object Dependencies {
   val JwtCoreVersion               = "11.0.2"
   val NettyVersion                 = "4.2.5.Final"
   val ScalaCompatCollectionVersion = "2.13.0"
-  val ZioVersion                   = "2.1.20"
+  val ZioVersion                   = "2.1.21"
   val ZioCliVersion                = "0.7.2"
   val ZioJsonVersion               = "0.7.44"
   val ZioParserVersion             = "0.1.10"