Update zio, zio-streams to 2.0.21 (#361)

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

Author: scala-steward

build.sbt

@@ -137,8 +137,8 @@ lazy val zio = project
     name := "colibri-zio",
     libraryDependencies ++= Seq(
       "io.github.cquiroz" %%% "scala-java-time" % "2.5.0",
-      "dev.zio"           %%% "zio"             % "2.0.19",
-      "dev.zio"           %%% "zio-streams"     % "2.0.19",
+      "dev.zio"           %%% "zio"             % "2.0.21",
+      "dev.zio"           %%% "zio-streams"     % "2.0.21",
     ),
   )